A  PRACTICAL  TREATISE 


BRICK,  TILES,  AND  TERRA-COTTA. 

i 


0      Q. 


A  PRACTICAL  TREATISE 

ON   THE 

MANUFACTURE  OF 

BRICK,  TILES  AND  TERRA-COTTA: 

INCLUDING 

STIFF-CLAY,  DRY-CLAY,  HAND-MADE,  PRESSED  OR  FRONT  AND  ROADWAY  PAVING  BRICK, 
ENAMELED-BRICK,  WITH   GLAZES  AND   COLORS,  FIRE-BRICK,  AND  BLOCKS,  SILICA- 
BRICK,  CARBON-BRICK,  GLASS-POTS,  RETORTS,  ARCHITECTURAL   TERRA-COTTA, 
DRAIN-TILE,  GLAZED  AND  UNGLAZED  ROOFING  TILE,  ART  TILE,  MOSAICS, 
AND    IMITATION    OF    INTARSIA,    OR    INLAID    SURFACES; 

COMPRISING   EVERY   PRODUCT  OF  CLAY   EMPLOYED   IN 

ARCHITECTURE,  ENGINEERING,  AND  THE  BLAST  FURNACE, 

WITH    A    DETAILED    DESCRIPTION    OF    THE    DIFFERENT    CLAYS    EMPLOYED,    THE   MOST 

MODERN    MACHINERY,    TOOLS,    AND    KILNS   USED,    AND   THE   PROCESSES    FOR 

HANDLING,   DISINTEGRATING,   TEMPERING,    AND    MOULDING    THE 

CLAY   INTO   SHAPE,   DRYING,    SETTING   AND   BURNING. 

BY     , 

CHARLES  THOMAS  DAVIS, 

THIRD  EDITION.     REVISED  AND  IN  GREAT  PART  RE-WRITTEN. 
ILLUSTRATED  BY  TWO  HUNDRED  AND  SIXTY-ONE  ENGRAVINGS. 


PHILADELPHIA : 
HENRY   CAREY  BAIRD  &   CO., 

INDUSTRIAL  PUBLISHERS,  BOOKSELLERS  AND  IMPORTERS, 
No.  810  WALNUT  STREET. 

LONDON : 

SAMPSON  LOW,  MARSTON  &  CO.,  LIMITED, 

ST.  DUNSTAN'S  HOUSE,  FETTER  LANE,  FLEET  STREET. 

1895. 


Mj^x 

UNIVERSITY) 

c.ALfFORNiA^^ 


•\ 


y 


V 


COPYRIGHT  BY 

CHARLES  THOMAS  DAVIS. 
1895. 


PRINTED  AT  THE 

WICKERSHAM  PRINTING  HOUSE, 

53  and  55  North  Queen  Street, 

LANCASTER,  PA.,  U.  S.  A. 


PREFACE  TO  THE  THIRD  EDITION. 


THE  fact  of  the  sale  of  two  editions  of  the  Practical  Treatise 
on  Brick,  Tiles  and  Terra-Cotta,  coupled  with  a  continued  de- 
mand for  copies  after  the  exhaustion  of  those  editions,  may  be 
taken  as  conclusive  evidence  of  the  acceptance  which  it  has 
met  with  among  the  trade,  and  that  other  considerable  body  of 
persons  who  are  interested  in  the  manufacture  and  use  of  brick, 
tiles  and  terra  cotta.  , 

The  United  States  is  rapidly  earning  a  reputation  for  com- 
fortable homes  and  beautiful  architecture,  and  brick  is  the  ma- 
terial out  of  which  they  are  usually  constructed  and  ornamented 
— for  terra  cotta  is  only  another  name  for  brick  which  have 
been  enriched  by  the  hand  of  the  artist.  Brick  is  also  the 
material  out  of  which  are  built  our  massive  temples  of  trade 
and  commerce,  our  magnificent  temples  of  religion,  and  our 
palaces  of  art  and  learning. 

Brick  made  of  suitable  clay  or  shale  and  thoroughly  burned 
are  also  rapidly  coming  into  use  as  the  material  with  which  to 
pave  our  public  roadways,  a  substance  which  is  cheap  and 
easily  repaired  and  which  possesses  almost  unlimited  endurance 
under  even  the  heaviest  traffic. 

The  chapters  on  Clay,  Tempered-clay  Brick,  Fire-Brick, 
Enameled-Brick,  Street  Paving  Brick,  Pressed  Brick,  Terra- 
Cotta,  and  Roofing-Tile  have  been  entirely  rewritten,  and 
every  other  portion  of  the  volume  has  had  such  thorough  re- 

(iii) 


IV  PREFACE  TO   THE  THIRD   EDITION. 

vision  as  to  bring  it  up  to  the  present  advanced  state  of  the 
various  branches  of  the  Clay  Industry. 

In  its  new  and  improved  shape  it  is  with  much  confidence 
believed  that  it  must,  in  the  present  and  the  future,  even  more 
than  in  the  past,  commend  itself  to  and  be  useful  to  those  for 
whom  it  has  been  specially  prepared. 

CHARLES  THOMAS  DAVIS. 

WASHINGTON,  D.  C. 
603  Seventh  Street,  May  13,  1895. 


tfflflf 


CONTENT-S. 


CHAPTER    I. 

THE  HISTORY  OF  BRICK. 

PAGE 

The  history  of  the  art  must  be  traced  back  to  the  delta  of  the  Nile; 
In  Egypt  the  art  of  pottery  credited  to  the  gods;  Num,  the  oldest  of 
created  beings,  the  first  to  practice  the  potter's  art  .  .  •  .  ...  i 

Proof  of  the  art  of  pottery  having  been  employed  prior  to  the  historical 
period;  Early  employment  of  brick;  History  of  brickmaking  analo- 
gous to  that  of  civilization ;  Authentic  record  of  this  branch  of  pot- 
tery older  than  that  of  any  other  ceramic  production ;  Descendants  of 
the  sons  of  Noah  the  first  potters  of  record;  Washington  monument 
and  similar  undertakings  compared  with  the  conceptions  of  the  bold 
men  of  2247  B.  C.;  Progress  in  the  art  of  brickmaking  .  .  ,  .  %.  9: 

Brickmaking  the  hardest  kind  of  work;  Servitude  of  the  children  of 
Israel,  in  Egypt,  in  making  brick  without  straw,  1491  B.  C.;  Pictures 
on  the  tombs  of  Thebes,  representing  the  method  of  making  brick; 
Rameses  II.  . '  .  .  .  '  .  •  •  •  •  •  •  3 

Mud  of  the  Nile  the  only  material  in  Egypt  suitable  for  brickmaking; 
Process  of  making;  The  brick  of  ancient  and  modern  Egypt  are 
adobes;  Herodotus  on  the  brick  used  in  the  walls  of  Babylon;  Extra- 
ordinary mounds  of  brick  at  Birs  Nimrod,  the  supposed  site  of  Baby- 
lon; The  buried  palaces  of  Nebuchadnezzar  supplying  the  brick  for 
building  the  city  of  Hillar;  Gathering  brick  from  these  ruins  the  sole 
trade  of  some  men;  Glazed  brick  in  the  ruins;  Brick  in  the  walls  of 
Bagdad  showing  the  stamp  of  Nebuchadnezzar;  Principal  colors  of 
Babylonish  brick  .  ,,.  .  .  .  .  .  .  •  4 

The  primary  colors  chiefly  used  in  ancient  Egyptian  decorations; 
Colored  decoration  the  distinctive  feature  of  Babylonish  architecture; 
Cuniform  inscriptions  impressed  in  the  brick;  Sizes  of  Babylonish 
brick;  Manner  of  laying  the  brick;  Use  of  bitumen;  Triangular  and 
wedge-shaped  brick,  the  latter  used  in  arches;  Recent  excavations  on 
the  site  of  Pithon,  the  treasure  city  of  Rameses  II. ;  Structures  built  of 
adobes,  some  without  straw;  The  brick  of  which  the  pyramids  are 
constructed  •...-.,  .  ;  .  .  .  .•..»••.  .  5 

The  valley  of  the  Nile  and  the  plains  of  Assyria,  the  seats  of  a  remote 

(v) 


yi  CONTENTS. 

PAGE 

brick  industry;  Chief  employment  for  brick  in  Assyria;  Process  of 
making  brick  in  Assyria 6 

Term  for  bride  in  hieroglyphs  and  its  meaning;  Brickmaking  probably 
a  royal  monopoly  in  Egypt;  Brick  impressed  with  the  praenomens 
and  names  of  Egyptian  monarchs;  Brick  made  during  the  reign  of 
Thothmes  III.  impressed  with  his  cartouche;  Dimensions  and  weight 
of  an  Egyptian  brick  in  the  British  Museum;  Investigations  of  M. 
Place 7 

Imperfect  character  of  unburnt  brick  and  manner  of  supplementing  the 
buildings  in  which  they  were  employed;  Ventilating  tunnels  in  Chal- 
dean buildings  to  dissipate  moisture;  Use  of  stucco  for  the  protection 
of  unburnt  brick;  Composition  of  the  stucco  used  in  Nineveh  .  .  8 

Causes  to  which  the  perfection  of  ancient  brickmaking  may  have  been 
due;  Brick  used  in  constructing  the  Great  Wall  of  China;  Sun-dried 
brick  of  Spain  and  Spanish  America;  Use  of  adobes  in  Texas  and 
Kansas  at  the  present  day .  .  9 

"Dobies"  of  the  Western  States;  Brick  not  in  favor  with  the  ancient 
Greeks;  Roman  brick;  Construction  and  height  of  buildings  in  Rome.  10 

Burning  brick  in  kilns  probably  of  Roman  origin;  Opus  reticulatum  ; 
Opus  lateritium  ;  Pliny  on  the  character  of  the  brick  made  in  Greece 
at  his  time;  Employment  of  "  salmon  brick  "  for  party -walls;  Brick  of 
the  first  century  of  the  Christian  era  .  .  .  .  .  .11 

Roman  tiles;  Gradual  change  in  the  shape  of  brick;  Roman  buildings 
of  concrete  faced  with  brick;  Roman  brick  work  of  the  first  two  cen- 
turies of  the  Christian  era  superior  to  any  other;  Deterioration  in 
brick  work  in  the  fourth  century;  Old  material  in  the  Arch  of  Constan- 
tine;  Knowledge  of  the  art  of  brickmaking  lost  to  Western  Europe; 
Brick  made  by  the  Romans  in  Germany  and  England;  No  evidence 
of  brickmaking  in  England  between  the  Roman  times  and  the 
thirteenth  century;  Re-use  of  Roman  brick  at  Colchester  and  St.  Al- 
ban's  Abbey;  Materials  used  in  the  buildings  of  the  Anglo-Saxons; 
Earliest  stone  buildings  of  Western  Europe,  after  the  time  of  the 
Romans  .  .  .  .  ;  4  .  „  ...  .  .12 

Improbability  of  brickmaking  in  England  in  the  reign  of  Alfred  the 
Great;  Earliest  brick  building  existing  in  England;  Progress  in  the 
manufacture  of  brick  under  Henry  VIII.  and  Elizabeth;  Good  exam- 
ples of  English  brick  architecture  in  mediaeval  times;  Beautiful  speci- 
mens of  brick  work  in  the  ecclesiastical  and  palatial  architecture  of 
Italy .13 

Regulation  of  the  size  of  brick  in  England  by  Charles  I.,  in  1625;  Uni- 
versal use  of  brick  in  the  reconstruction  after  the  great  fire  of  London, 
1666;  Tax  on  brick  from  1784  to  1850;  Building  materials  of  a  town 
dependent  upon  the  geology  of  the  surrounding  district;  Brick  the 
chief  building  material  of  Holland;  The  City  Hall  of  Amsterdam,  as 
described  by  Peter  Mortier .  .14 


CONTENTS.  vii 


First  brick  buildings  erected  in  America  under  Governor  Van  Twiller; 
Wages  of  carpenters  and  bricklayers  regulated  by  Governor  Win- 
throp;  Brickmakers  first  recorded  as  part  of  the  population  in  the 
colony  of  New  Haven  .........  15 

Their  efforts  and  failures  at  brickmaking;  Brick  brought  from  England 
to  Virginia;  Preference  for  brick  as  a  building  material  in  Philadel- 
phia; William  Penn's  description  of  a  house  to  be  built  for  a  lady 
about  to  emigrate;  Bricklayers'  wages  and  price  of  brick  in  Philadel- 
phia, in  1705 .  16 

The  old  court  house  in  Philadelphia  one  of  the  earliest  brick  buildings 
in  this  country;  State  House  or  Independence  Hall;  Great  Meeting 
House  of  Friends;  Great  Towne  House;  Brick  for  foot  pavements  in 
Philadelphia,  in  use  in  1719;  Wood  the  favorite  building  material  in 
colonial  days  in  Boston;  The  " Towne  House,"  Boston;  The  "Old 
State  House,"  Boston  .  .  ....  .  ....  17 

First  Episcopal  church  and  the  "Triangular  Warehouse,"  Boston;  Gen- 
eral introduction  of  brickwork  in  this  country;  Importation  of  brick  as 
ballast,  from  England;  Condition  of  building  prior  to  and  succeeding 
the  Revolution;  Change  in  the  condition  of  things  after  the  adoption 
of  the  Constitution;  General  employment  of  home-made  brick  .  18 

American  brick,  at  present,  superior  to  those  of  any  other  country;  The 
advantages  of  the  American  patent  system;  Ijttle  attention  paid  to 
improvements  in  modes  or  machines  for  manufacturing  common  brick 
until  about  1835;  Some  early  types  of  machines  .  .  .  .19 

Revolution  in  the  mode  of  manufacturing  brick  during  the  past  twenty 
years;  Nathaniel  Adams'  brick  machine,  invented  in  1835,  and  its  de- 
struction by  a  mob;  Growth  of  the  brick  industry  and  consumption  of 
brick  in  the  leading  cities  of  this  country;  Brickmakiug  in  the  South.  20 

Tendency  to  frame-construction  in  some  Southern  States;  Increase  in 
the  demand  for  brick  and  its  causes;  Difference  between  road  paving 
and  building  brick;  Most  popular  kind  of  paving-brick  at  the  present 
time £,  ...  21 

Basis  upon  which  the  present  boom  in  brick  pavements  has  been  built; 
Market  for  paving  brick  largely  in  the  hands  of  interested  parties;  In- 
troduction of  the  use  of  brick  for  street  pavements  .  .  .22 

Classes  of  streets  which  have  to  be  paved  during  the  present  decade; 
Peculiar  manner  of  making  very  hard  and  durable  brick  at  El  Paso, 
Texas;  Requirements  of  the  brick  industry  at  the  present  day  .  23 

Brickmaking  revolutionized  by  machinery          ......     24 

Necessity  of  a  thorongh  knowledge  of  the  clay 25 


viii  CONTENTS. 

CHAPTER   II. 
CLAY. 

PAGE 

BUILDING-BRICK  CLAYS;  HUDSON  RIVER  CLAYS;  PAVING-BRICK  CLAYS; 
FIRE  CLAYS;  METHOD  OF  ANALYSIS  FOR  FIRE  CLAYS,  FELDSPARS, 
KAOLIN  AND  FIRE-SANDS;  TERRA-COTTA  CLAYS;  KAOLIN  OR  CHINA 
CLAY. 

What  is  understood  under  the  general  term  clay;  Characteristic  prop- 
erty of  clay;  Purest  clay  found  in  nature;  Derivation  of  the  word 
"Clay;"  Compounds  present  in  clays;  Division  of  clays  in  geological 
works  ...*.........  26 

Classes  into  which  clays  are  technically  separated;  Constitution  of  the 
major  portion  of  the  insoluble  residue  left  after  the  decomposition  of 
feldspathic  rocks;  Causes  to  which  the  various  shades  of  color  of  clay 
are  due;  Deposition  of  clay  and  its  occurrence;  Plastic  power  of  clay; 
Fat  and  lean  clays  .  .  .  .  .  .  .  .  .  .  27 

L/inear  shrinkage;  Limits  of  shrinkage;  Water  of  shrinkage;  Water  of 
pores;  Shape  of  the  minute  particles  of  clay  substance;  Number  and 
size  of  the  pores  independent  of  the  water  in  the  clay;  Increase  in 
shrinkage  up  to  a  certain  point ;  Fire  shrinkage  and  its  neutraliza- 
tion ;  The  state  in  which  iron  is  contained  in  ordinary  yellow  brick 
clays !,  ..'"".  .28 

Cause  to  which  the  red  color  of  brick  is  due;  Principal  constituent  of 
brick  clay;  Beneficial  effect  of  a  proper  proportion  of  sand  and  a  small 
quantity  of  carbonate  of  lime;  Injurious  ingredients  of  brick  clay; 
Presence  of  common  salt  in  clay  and  its  effects  upon  the  brick;  Effect 
of  alkaline  carbonates  in  clay  .  .  .  .  .  .  .  .  29 

Occurrence  of  rare  minerals  in  clay;  Classes  of  building  brick  clays; 
Malm;  Non-existence  in  nature  of  a  clay  fit  for  the  manufacture  of  a 
first-class  quality  of  building  brick;  Properties  of  a  good  brick-clay; 
Brick  of  pure  or  "foul  clays;  "  On  what  the  color  of  brick  depends.  30 

White  brick;  Tint  produced  by  the  presence  of  iron;  Proportion  of 
lime  and  magnesia  in  the  clays  from  which  Milwaukee  cream-colored 
brick  is  made;  Constituents  of  the  average  brick  clays  of  the  drift; 
Lithia  in  Ohio  clays;  The  knowledge  of  the  composition  and  proper- 
ties of  clay  now  current  among  the  manufacturers  .  .  .  .31 

Clay  the  result  of  decomposition  of  granite  rocks;  Constitution  of  ortho- 
clase;  Agencies  sufficient  to  decompose  feldspars;  Mineral  elements 
in  granite  and  gneiss;  Cause  of  the  irregularity  of  composition  char- 
acteristic of  clay .  32 

Qualifications  for  a  clay  for  building  brick;  Objections  to  clays  contain- 
ing a  large  amount  of  carbonaceous  matter;  Hindrance  of  carbonate 
of  lime,  diffused  limestone  and  lime  pebbles  in  brick  clays  to  the 
production  of  even  a  passable  quality  of  building  brick  .  -33 

Selecting  clays  for  various  kinds  of  building  brick;  Clay  for  common 


CONTENTS.  ix 


mud  brick;  Determination  of  the  pugging  qualities,  plasticity  as  well 
as  moulding  and  drying  qualities  of  clays;  Determination  of  the 
color  to  which  a  brick  will  burn ;  Material  for  brick  to  be  manufac- 
tured by  the  soft-clay  process;  Clay  for  the  stiff-clay  and  dry-press 
brick  machines  ...........  34 

Conditions  necessary  for  the  successful  manufacture  of  the  best  classes 
of  front  brick;  Considerations  to  be  regarded  in  erecting  works  for 
the  manufacture  of  building  brick;  Testing  the  nature  and  the  quan- 
tity of  the  clay  by  boring  .  .  .  .,  V  .'•'"."  .  35 

Hudson  river  brick  clays,  their  occurrence  and  properties      ,         ..         .36 

Relative  qualities  of  the  blue  and  yellow  varieties  of  clay;  Favorable 
location  of  the  Hudson  river  clays;  Little  difficulty  in  prospecting  for 
clay  along  the  Hudson  river  .  .  .  .  < .  _  ,f  .  ,  •  37 

Paving  brick  clays;  Shale  clays  in  the  United  States;  Mr.  J.  H.  Calkins 
on  clay  for  paving  brick,  and  Mr.  W.  H.  Budaly  on  the  same  subject.  38 

Mr.  F.  B.  Frey  on  the  mixing  and  manipulation  of  different  clays  for 
the  manufacture  of  street-paving  brick;  Mr.  Shea's  ideas  on  the  same 
subject;  Mr.  W.  D.  Gates's  advice  • '."  „  .  V  .  .  .  -39 

Mr.  A.  O.  Jones,  on  clays  for  paving-brick ;  Mr.  George  S.  Tiffany,  on 
the  manufacture  of  vitrified  street  paving-brick  .  .  .  .40 

Requisite  properties  of  clay  for  paving-brick          .         .         .         .         .41 

Clay  used  at  Galesburg,  111. ;  Clay  of  the  Diamond  Brick  Company,  of 
Kansas  City,  Mo.;  Clays  at  Atchison,  Kans.,  and  at  Sioux  City,  Iowa.  42 

Clay  at  Des  Moines,  Iowa;  Clay  at  Middlsport,  Ohio,  worked  by  Garrett 
&  McMonigal  .  'V  '.-''.- 43 

Clay  used  in  making  paving-brick  at  Westerville,  Ohio,  by  Mr.  J.  W.  Emer- 
ald; Analysis  of  shale-clay  used  by  the  Bucyrus  Brick  and  Terra-Cotta 
Co.,  of  Bucyrus,  Ohio;  Analysis  of  shale  used  at  Fort  Smith,  Ark.  .  44 

Shale  from  the  ore  mines  of  the  Cambria  Iron  Company,  of  Johnstown, 
Pa. ;  Shale-clay  of  the  Grape  Creek  Clay  Company,  Grape  Creek,  111. ; 
Material  used  by  the  London  Clay  Company,  of  London  Mills,  111.,  for 
making  paving-brick;  Fire-clays;  Definition  of  the  term  fire-clays  or 
refractory  clays;  Occurrence  of  fire-clays;  On  what  the  fictile  or  plastic 
property  of  clays  depends  .........  45 

Expulsion  of  hygroscopic  water;  Loss  of  plasticity  by  dehydrated  clay; 
Variation  in  the  composition  and  quality  of  clay  from  contiguous  beds 
in  the  same  pit;  Geological  formations  of  fire-clays;  Colors  of  fire- 
clays .  *  .  .  .  .  .  .  •  •  •  •  .46 

Distinct  varieties  of  fire-clay;  Occurrence  of  superior  qualities  of  fire- 
clay.in  the  United  States;  Location  of  fire-brick  plants;  Works  of  the 
Harbison  &  Walker  Co. ;  Superiority  of  the  fire-clays  of  Mount  Sav- 
age, Md.,  of  the  "Amboy"  clay  of  New  Jersey  and  of  Farrandsville, 
Pa. ;  Fire-clay  found  at  Mineral  Point,  Tuscarawas  county,  Ohio,  and 
at  New  Lisbon,  Ohio  :. .  '•.•-•'  ••*  .  •  »  •"••  V,  ;•  •  •  «  47 

"Cement"  for  fire-clays;   Fire-brick  made  from  the  coal  measures  of 


CONTENTS. 


various  states;  Analysis  of  Farrandsville,  Pa.,  fire-clay  by  J.  Blodget 
Britton;  Mount  Savage  clay,  its  occurrence,  and  analysis  of  it  .  48 

Varieties  of  Mount  Savage  fire-clay  and  their  properties.         .         .         -49 

Peculiarity  of  the  Mount  Savage  deposit;  Impurities  of  Mount  Savage 
clay;  Reason  for  the  superior  quality  of  the  clay;  Tests  made  by 
Robert  Anderson  Cook 50 

Formula  for  the  calculations  in  getting  at  the  value  of  a  fire-clay  from 
its  analysis;  Usefulness  of  such  calculations  in  the  comparison  of  dif- 
ferent clays;  Necessity  of  testing  the  physical  qualities  of  all  clays.  51 

Difficulties  the  brickmaker  has  to  contend  with;  Furnace  for  making 
tests 52 

Difficulty  of  spotted  brick  in  supplying  the  present  demand  for  hard- 
burned  brick;  Important  properties  of  fire-clays.  .  .  .  '53 

Influence  of  free  silica  in  fire-brick;  Necessity  of  making  two  analyses 
of  the  silica  in  a  fire-clay;  Variation  in  the  relation  between  the  silica 
and  the  alumina  and  in  the  quantity  of  water 54 

Non-importance  of  organic  matter  in  clay;  Composition  of  clay  which 
is  most  refractory  when  deprived  of  its  hygroscopic  water;  Power  of 
clay  to  resist  heat.  .....  .  .  *.  •  •  -55 

Value  of  a  given  refractory  clay;  Unusual  amount  of  iron  in  an  excel- 
lent clay  from  Spain;  Analyses  of  two  clays  in  great  demand;  Re- 
quisite properties  of  a  clay  to  be  useful.  .  .  .  .  .  .56 

Characteristics  of  all  fire-clays.         .         .         .         .         .        .         .         .     57 

Necessity  of  analysis;  Bischoff's  assay  and  the  foil  assay;  Type-clay  for 
Bischoff 's  assay;  The  density  of  a  clay  an  important  element  of  con- 
sideration; Density  of  Stourbridge  clay,  Coblentz  clay  and  Missouri 
clays 58 

Method  of  determining  the  specific  gravity  of  clays;  Bond  clay;  The  fact 
upon  which  the  problem  of  making  a  refractory  brick  from  native 
clays  is  based;  Properties  of  a  clay  fit  for  a  bond.  .  .  .  •„,  .  59 

Structure  of  the  fire-brick  in  its  relation  to  the  base  of  a  first-class  brick 
and  to  the  bond  clay;  Preparation  of  the  flint-clay;  Object  of  the  wet 
pan 60 

Screens  in  general  use;  Advantage  of  a  circular  revolving  screen;  Dig- 
ging, mining  and  marketing  fire-clays;  Removal  of  the  superficial 
beds  or  "bearing."  ;  .  ........  61 

Digging  by  a  succession  of  contiguous  pits;  cost  of  removing  the  top 
dirt;  Employment  of  steam  excavators  in  removing  the  top  dirt;  Loca- 
tion of  the  heaps  of  top  dirt  or  dumpings;  Mining  of  clay  by  digging 
small  pits.  .  .  .  .  .  .......  •  .  ''+  .  .62 

Depth  of  the  pits;  Platform  for  sorting  the  material  thrown  out;  Spade 
used  in  digging;  Different  modes  of  digging.  .  .  ...  .63 

Strengthening  the  sides  or  the  walls  of  the  pits  or  banks;  Use  of  the 
pick  and  of  blasting  powder;  Undermining  by  wedges  and  powder; 
Removal  of  water  from  the  pits.  .1 '  .;."  .  .  .  .  .64 


CONTENTS.  xi 

PAGE 

Various  modes  of  raising  water;  Extraction  of  clay  by  underground 
work  or  mining.  ...........  65 

Timbering;  Objections  to  the  extraction  of  clay  by  underground  mining; 
Digging  of  fire-sand,  kaolin,  and  feldspar;  Tools  used  in  digging  these 
materials.  .  ............  66 

Mode  of  shipping  clays,  feldspar,  kaolin  and  fire-sand;  necessity  of  keep- 
ing fire-clay  mines  in  first-class  condition;  Care  required  in  fire-clay 
mining;  Streaks  or  spots  in  fire-clay  mines,  .....  67 

Fire-clay  mines  of  the  Glenboig  Union  Fire-Clay  Company,  Limited,  of 
Glasgow,  Scotland;  " Stoop-and-room  "  or  "  pillar  and-stall "  system 
of  working;  Pumping  of  water;  Raising  the  fire-clay.  .  .  .  .  68 

Table  of  analyses  of  fire-clays  and  associated  refractory  materials,  made 
in  the  laboratory  of  the  Geological  Survey  of  New  Jersey  .  .  .  70 

Value  of  these  analyses;  Necessity  of  supplementing  the  analyses  by 
fire  tests;  Mode  of  fire  tests  in  a  crucible  steel  furnace,  at  the  Newark 
Steel  Works;  Results  of  these  tests  .  .  ...  .  "  .  -77 

Method  of  analysis  for  fire-clays,  feldspars,  kaolin  and  fire-sands  .         .     78 

Terra-cotta  clays;  Analysis,  by  Weston,  of  the  potter's  clay  of  North 
Devon  and  Dorsetshire;  Material  used  in  the  production  of  terra- 
cotta in  the  north  of  England  and  in  Scotland;  Advantage  of  a  care- 
ful and  thorough  mixture  of  clays  . 80 

Desirability  of  a  partial  vitrification  of  the  mass;  Great  variety  of  clays 
and  extent  of  area  in  New  Jersey;  Average  depth  of  the  deposits  and 
order  of  supersession  ..,,'..  .  .  .  .  .  .  .81 

Average  price  per  ton;  Value  of  production  of  fire-clays;  Manufacture 
of  lumber  from  clay  by  the  New  York  Terra-Cotta  Lumber  Company; 
Woodbridge  and  Perth  Amboy,  N.  J.,  deposits  of  clay,  their  accessi- 
bility and  richness;  Various  colors  of  New  Jersey  clays  .  .  .82 

Explanation  of  the  term  "going  through  the  sweat."      .         .         .         .83 

Vitrifying  ingredients  that  are  usually  added  to  terra-cotta  clays; 
"Grog; "  A  material  of  a  minimum  shrinkage  in  drying  and  burning 
required  for  terra-cotta;  Standard  texture  and  hardness  for  architec- 
tural terra  cotta  .  .  .  .  .  .  .  .  .  .  .84 

Properties  of  terra-cotta;  Kaolin  or  China  clay;  Origin  of  kaolin; 
Kaolin  of  Cornwall,  England,  and  of  Limoges,  France:  Formula  of 
clays  much  valued  by  porcelain- makers;  Explanation  of  the  term 
kaolin,  when  used  by  practical  potters  .  .....  85 

Occurrence,  consumption  and  price  of  China '  clays  in  the  United 
States;  Test  for  ascertaining  the  value  of  such  clays  .  .  86 

CHAPTER    III. 

MAKING  AND  BURNING  A  KILN  OF  HAND-MADE  BRICK. 

Necessity  of  different  methods  of  manufacturing  by  hand;  Preparation 
of  the  clay;  Preparation  of  the  "floors;"  Wintering  or  weathering 
clay  .  .  ...  ^__^_-  ....  87 


U.NIVERSITT) 


xii  CONTENTS. 


Commencement  of  the  brickmaking  season  in  the  Middle  States;  Tem- 
pering the  clay;  Various  methods  employed;  Work  of  the  hand- 
temperer  .  .  ..........  88 

Tempering  with  a  pug-mill  and  ring-pits;  Their  capacity  and  mode  of 
operation;  Object  of  tempering;  Moulding  the  clay;  Duties  of  the 
moulder  .  .  .  .........  89 

Duties  of  the  wheeler  and  the  moulding  gangs;  Various  modes  of 
moulding,  and  the  moulds  employed  .  .  .  .  .  90 

Moulding  cleat  and  plane  illustrated  and  described;  Duties  of  the 
"off-bearer." 91 

What  constitutes  a  day's  work  for  each  moulding  gang;  Constitution  of 
a  moulding  gang;  Necessity  of  watching  the  off-bearing  boys;  Dry- 
ing the  brick  ;  . 92 

Washed  brick;  Form  of  drying  shed          .......     93 

Improved  forms  of  drying  sheds;  "Slop"  method  of  moulding  brick; 
Pallets  .  ,  .  .  .  .  .  i  .  .  .  .94 

Setting  the  green  brick  in  the  kiln;  "Pillar"  brick  and  "skintles" 
illustrated  and  described;  Tie  course;  Lower  bench;  Upper  bench.  95 

Ten  courses  of  common  brick  set  on  the  bench  in  the  kiln  described 
and  illustrated;  Duty  of  the  setting  gang;  Plastering  and  daubing 
the  kiln  .  .  .  , .  96 

"Closing  the  bestowing;"  Burning  the  bricks;  Description  of  brick 
kilns t  •  '.  .  .  .  .  -  •  97 

Firing  the  kiln;  Directions  for  burning  brick;  Period  when  the  kiln  is 
said  to  be  hot  .  .  .  .  .  .  .  •  >•  •  •  9$ 

Illustration  of  and  use  of  a  "moon;"  Detection  of  and  remedy  for 
"  cold  places "  in  a  burning  kiln  ,  ...  .  .  -99 

Quantity  of  air  to  be  admitted  into  the  kiln  during  burning;  "Settling 
fires,"  when  applied;  Proper  amount  of  settling  .  .  ,  .  100 

Other  methods  for  burning  brick  by  combinations  of  gas  and  air,  etc. 
Amount  of  coal  required  to  burn  a  kiln  of  hand-made  brick;  Tools 
and  appliances  used  in  the  manufacture  of  hand-made  brick  .  .  101 

Moulder's  lute  described  and  illustrated;  Division  of  the  time  of  the 
men  around  the  burning  kiln;  "Head  fires"  and  use  of  the  short 
moon  .............  102 

Other  tools  required;  Pug-mills          .         .        ,        .        .        ,        .        .  103 

Improvement  in  the  construction  of  pug-mills  invented  by  Mr.  Alfred 
Hall  of  Perth  Amboy,  N.  J.,  described  and  illustrated  ,  .  .  104 

"Sizing  the  clay;"  Duties  of  the  temperer  for  the  pug-mill;  Motive 
power  for  pug-mills  .  .  ...  .  .  .  .  .  107 

Tools  required  by  each  temperer;  Tempering  clay  by  ring-pits;  Descrip- 
tion of  ring-pits  . 108 

Raymond  tempering  wheel  described  and  illustrated  .        .         .   109 

Difficulties  in  the  use  of  ring-pits;  No  separate  temperers  required  for 
ring-pits  .  .  .  .  .-...*'.  .  .  .  .no 


CONTENTS.  Xlil 

PAGE 

Preference  of  brick-yard  laborers  for  clay  tempered  in  ring-pits;  Inven- 
tion of  Mr.  Henry  Aiken,  of  Philadelphia,  Pa.,  relating  to  improve- 
ments in  ring-pits,  described  and  illustrated  .  .  .  .  .  in 

CHAPTER    IV. 

MANUFACTURE  OF  TEMPERED-CLAY  BRICK ;  INCLUDING  A  DE- 
SCRIPTION OF  THE  MOST  MODERN  MACHINERY  EMPLOYED. 

General  remarks;  Corner  stones  of  financial  success  in  the  business  of 
brickmaking;  Considerations  to  be  regarded  in  establishing  a  brick- 
making  plant;  Dependence  of  the  manufacturer  of  common  building 
brick  upon  home  consumption  .  .  .  l  .  .  .  .  .  115 

Reasons  why  the  pressed-brick  manufacturer  has  a  more  extended 
market;  A  safe  and  reliable  basis  as  regards  machinery  reached  in  the 
business  of  brickmaking;  Classification  of  the  different  kinds  of 
brick  machines  .  .  .  .  .  .  .  .  •  .  .  116 

Drawbacks  in  modern  machinery;  Division  of  the  process  of  manufac- 
turing bricks  by  machinery;  Mining  clay  for  building-brick;  Diffi- 
culty of  obtaining  a  sufficient  supply  of  clay  .  v  ,  .  .  .  .117 

Dangers  of  digging  and  consequent  difficulty  in  employing  labor; 
Barnhart  steam  shovel,  described  and  illustrated  .  .  .  .118 

Substitution  of  electric  power  for  steam  in  operating  steam  shovels; 
Hauling  clay;  Plowing  clay  .  ,T  .  .  .  .  .  .  .119 

Winding  drums  and  dump  cars;  Friction  winding  drum  of  the  Frey- 
Sheckler  Co.,  described  and  illustrated  ......  120 

Gear  and  friction  winding  drum  of  the  Frey-Sheckler  Co.,  described 
and  illustrated 121 

Side-dumping  clay  car  of  the  Frey-Sheckler  Co.,  described  and  illus- 
trated .  .  .  '. 123 

Bottom-dumping  clay  car  of  the  Frey-Sheckler  Co.,  described  and 
illustrated  , 124 

Tempering  and  preparing  clay;  Old  methods  of  tempering;  Clay 
crushers;  Necessity  for  some  device  which  will  thoroughly  pull  the 
clay  apart  and  open  the  pores;  Proper  preparation  of  the  clay  .  .125 

The  old-fashioned  tempering  wheel;  Use  and  size  of  soak  pits;  Various 
methods  of  tempering  clay  .  .  .  .  .  •  •  •  .126 

Hot  water  tempering;  Simple  method  for  thawing  clay  .         .         .         .127 

Trouble  in  elevating  the  clay  to  the  disintegrator,  how  remedied;  Gran- 
ulating pug-mill  built  by  the  Frey-Sheckler  Co.,  described  and 
illustrated  .: I28 

Clay  crushers;  Two-roll  and  four- roll  crushers  of  the  Frey-Sheckler 
Co.,  described  and  illustrated I3° 

Pug-mills;  Pug-mill  built  by  the  Frey-Sheckler  Co.,  described  and 
illustrated  ....  .  ...  ."..»-.  .  *33 


xiv  CONTENTS. 


Double  geared  pug-mill  made  by  the  Frey-Sheckler  Co.  .         .         .135 

Moulding  stiff-clay  brick;  Requirements  of  brick  made  by  moulding 
machines;  Disintegration  of  brick  due  to  improper  construction  of 
moulding  devices;  Philosophy  of  the  flow  of  clay  through  the  dies, 
and  prevention  of  lamination  of  the  clav  in  the  brick          .         .         .   137 
Use   of   lubricating  dies;    Form  of  the  laminations;  Other  causes  of 
lamination        ............   138 

Die  for  end-cut  bricks  of  the  Giant,  Acme,  Centennial  and  Mascot 
machines;  Niedergesaess  lubricating  brick  die,  described  and  illus- 
trated   139 

Mascot  machine  with  daisy  cutting  table,  described  and  illustrated        .  141 
Improved  Centennial  brick  and  tile  machine,  described  and  illustrated.  143 
Improved  Acme  machine  built  by  the  Frey-Sheckler  Co.,  described  and 
illustrated          ....        .         .         .         .         .         .         .         .  145 

Special  Bucyrus  giant  machine,  described  and  illustrated        .         .        .  147 
Bucyrus  side-cut  automatic  table,  described  and  illustrated     .         .        .  149 
Wellsville  side-cut  table,  described  and  illustrated;  Drying  the  brick; 
Classification  of  the  different  methods;  Disadvantages  of  drying  in 

the  sun .        .        .        . :      .       -.         .  150 

The  pallet-system  for  soft-mud  brick;  General  advantages  of  artificial 

drying 151 

Difficulty  in  drying  machine-made  brick  for  re-pressing,  and  its  rem- 
edy; Final  drying  on  a  hot  floor    .        ...         .4         .         .  152 

Improved  brick-drying  shed,  with  detailed  description  and  illustrations.   153 
Drying  by  the  pallet  system         .         .         .  •:  "•-  .         .         .         .         .         .  156 

Description  of  the  pallets  and  drying  cribs;  Advantages  of  this  system 
of  drying;  Store  sheds     .         .         .        .  «      .        .         .         .         .         .  157 

Drying  brick  with  exhaust  steam  from  the  engine;    Construction  of 
steam-work  for  dryers,  described  and  illustrated  .....  158 

Steam  dry-floors;  Mode  of  construction,  by  Mr.  A.  Crossly,  of  Ironton, 
Ohio          .         .         .         .         ...        .         .        .        .         .         .  161 

Another  system  for  the  advantageous  use  of  exhaust  steam     .         .         .  162 
How  to  devise  a  dryer;  A  "flue"  and  "hot  floor"  dryer          .         .         .   163 
Plan  of  construction  for  such  a  dryer        .        ......  164 

Drying  brick  by  a  current  of  hot  air;  Bucyrus  dryer         .         .         .         .   166 

Brief  history  of  various  dryers;  Bucyrus  steam  tunnel  dryer,  described 

and  illustrated  .         .  ,"'    ' .         .   168 

Setting  brick  in  the  kiln;  Importance  of  proper  burning;  Mistake  in 

setting 169 

Manner  of  setting  benches,  with  detailed  description  and  illustrations.  170 
Setting  green  pressed  brick  in  the  kiln      .         .         .        ...         .         .171 

Cars  used  in  handling  brick  for  setting;  Description  of  cars   .         .         .  172 
Advantage  of  running  an  establishment  in  all  weathers;  Dry  car  made 
by  the  Frey-Sheckler  Co.,  described  and  illustrated      .         .         .         .173 

Wheelbarrows  with  descriptions  and  illustrations 175 


CONTENTS.  XV 


Burning  brick       ............  178 

Number  of  pounds  of  bituminous  coal  equal  to  one  cord  of  wood, 

statement  of  Mr.  W.  A.  Eudaly,  of  Cincinnati,  0 179 

Table  showing  the  value  and  properties  of  various  kinds  of  coal  .  .  180 
Coal  slack  for  fuel;  Recent  progress  made  in  burning  brick;  Square  top 

kilns  of  Wingard,  Morrison,  Eudaly  and  Melcher;  Amount  of  wood 

required  to  bnrn  the  yearly   product  of  brick;  Merits  of  the  round 

and  down-draft  kiln          .        .         .         .         .         .         .         .         .         .182 

Hoffman's  continuous  kiln;  Cost  of  burning  brick  in  the  Hoffman  kiln; 

Management  of  the  old  open-top  kiln    .         .         ;        .        .        .        .183 

Explanation  of  water-smoke       .         .         .         .         .        .        »        .         .  184 

Prevention  of  loss  of  heat;  Advantage  of  coloring  brick  with  a  lively 

heat;  Philosophy  of  combustion,  and  cause  of  the  discoloration  of  the 

brick  in  the  kiln       .         .         .         .         .         .        .        .....   185 

Burning  brick  with  natural  gas;  Composition  of  most  gases         .'       .   186 
Secret  of  successfully  burning  with  natural  gas          .....   187 

Experiments  in  burning  different  clays  with  natural  gas;  Applicability 

of  natural  gas  to  all  manner  of  kilns          .          .          .          .          .          .   188 

Cost  of  burning  with  natural  gas          .         .         .          .          .          .          .  189 

Experiments  of  burning  with  gas  by  Mr.  J.  R.  Boice,  of  Toledo,  Ohio, 

and  Mr.  G.  B.  Smith,  of  Haverstraw,  New  York  ....   190 

Burning  brick,  tile,  etc.,  with  crude  oil          ......  191 

Methods  of  overcoming  the  principal  obstacles;  Experiments  in  the  use 

of  petroleum  as  fuel,  by  Mr.  Chas.  S.  Purington,  of  Chicago,  111.  .  192 
Cost  of  burning  with  crude  oil;  S.  P.  Crafts,  on  the  use  of  crude  oil  as 

fuel  .  .  ...' 195 

Results  of  burning  brick  with  oil  obtained  by  Mr.  D.  V.  Purington,  of 

Chicago,  111.          ... 197 

CHAPTER  V. 

CHAMBERS'  BRICK  MACHINE- 

Inventions  of  Cyrus  Chambers,  Jr.,  of  Philadelphia,  Pa.;  Chambers' 
single  conical  rolls,  described  and  illustrated          .....  200 

Tempering  device  of  the  machine,  described  and  illustrated          .         .  202 
Peculiar  form  of  the  "former."         ........  203 

Chambers'  machine,   described  and  illustrated;   Chambers'  automatic 

wire  cut-off .         .         .205 

Chambers'  machine  fitted  with  the  automatic  wire  cut-off,  described 
and  illustrated  .  ...  208 


xvi  CONTENTS. 

CHAPTER  VI. 
MANUFACTURE  OF  STREET  PAVING-BRICK. 

PAGE 

Factors  on  which  the  successful  manufacture  of  vitrified  brick  for  road- 
way paving  depends;  Requisites  for  a  good  paving-brick       .        .         .  209 
Paving-brick   plant   construction;   General   features   as   given   by   Mr. 

Eudaly 210 

Starting  and  managing  a  plant;  Suggestions  of  Mr.  Wm.  H.  Brush,  of 

Buffalo,  N.  Y.,  and  of  Mr.  J.  A.  Reep 212 

Size  of  paving-brick;  Mr.  Shea  on  this  subject          .....  213 
Conveying  and  grinding  clay;  Mining  shale  clays  and  plastic  clays          .  214 
Dry-pan  made  by  the  Frey-Sheckler  Co.,  described  and  illustrated          .  215 
Improved  tailings  crusher,  described  and  illustrated          .         .         .         .217 
Mr.  G.  H.  Brown,  of  Sioux  City,  Iowa,  on  the  importance  of  the  thor- 
ough preparation  or  "  tempering  "  of  the  clay          ....  218 
Moulding  and  pressing;  Mr.  G.  H.  Brown  on  this  subject;  Use  of  stiff- 
clay  brick  machines  and  of  soft-clay  brick  machines;  Moulding  by 
any  of  the  ordinary  forms  of  sewer-pipe  machines          .        .         .         .219 

Reasons  for  the  necessity  for  re-pressing  paving-brick          . .        .  220 

Provisions  of  the  Chicago  Roadway  Paving  Ordinance;  Drying  paving- 
brick;    Advantages  of  artificial  drying          .         .         .      '   .         .         .  221 
Burning  paving-brick;  Water-smoking;  Cooling  the  kiln;  Emptying  the 
kiln;  Use  of  crude  oil  for  burning  vitrified  brick;  Fuel  gas  the  coming 
fuel  for  burning          .         .         .         .         .         .         .         .         .         .  222 

Mr.  E.  M.  Pike,  of  Chenoa,  111.,  on  the  difference  in  the  cost  of  burning 
paving-brick  and  common  hard  building-brick;  Mr.  A.  O.  Jones,  of 
Zanesville,  O.,  on  the  best  results  in  burning  street  paving-brick;  Use 

of  down-draft  kilns  in  Atchison,  Kansas 223 

Use  of  continuous  kilns  at  Sioux  City,  Iowa,  and  at  Beatrice,  Neb. ;  Mr. 
H.  Dawson,  Sr.,  of  Springfield  111.,  on  the  burning  of  paving-brick; 
Mr.  G.  H.  Brown,  of  Sioux  City,  Iowa,  on  the  same  subject          .         .  224 
Mr.  W.  A.  Eudaly,  of  Cincinnati,  Ohio,  on  burning  paving-brick;  Mr. 
D.  W.  Stookey  on  the  same  subject          .         .         .         .        .        f        .  225 

Annealing  paving-brick  .          .          .          .         .        i        .         .         .  228 

Methods   employed  by  various  manufacturers   of   paving-brick;    Mr. 
Beattie's  observations          .         .         .          .         ....         .          .         .  230 

Mr.  A.  O.  Jones'  practice;   Method  of  the  Grape  Creek  Clay  Company, 
of  Grape  Creek,  111  ;  Process  of  Messrs.  Stewart  &  Collins,  of  Hast- 
ings,  Neb.         .         ...'".       ..         .         .     •••„•••        •         ...         .         •  231 

Method  of  the  Evansville  Pressed  Brick  Co.,  of  Evansville,  Ind.         .  232 
Methods  of  the  Purington  Paving  Brick  Co.,  of  Galesburg,  111.,  and  of 
the  Ottumwa  Paving-Brick  and  Construction  Co.,  of  Ottumwa,  Iowa.  233 


CONTENTS.  xvii 


CHAPTER  VII. 

MANUFACTURE  OF  DRY-CLAY  BRICK. 

PAGE 

The  term  dry-clay,  to  a  certain  extent,  a  misnomer;  Introduction  of  dry- 
clay  brickmaking  into  St.  Louis;  Prejudice  against  it.  ...  235 

Present  preference  for  this  class  of  brick  in  St.  Louis;  Failure  frequently 
due  to  a  lack  of  proper  knowledge  among  manufacturers;  Importance 
of  burning  in  the  manufacture  of  brick  by  the  dry-clay  system.  .  236 

Examination  of  samples  of  different  kinds  of  dry-clay  brick;  Employ- 
ment of  dry-clay  salmon  brick  for  dwelling  houses  and  other  light 
work;  Selection  of  clay  for  making  brick  by  the  dry-clay  process.  .  237 

Preparation  of  the  clay;  Richardson's  advice  in  his  address  at  the 
Second  Annual  Meeting  of  the  National  Brick  Manufacturers'  Asso- 
ciation; Manipulation  of  the  clay  upon  the  drying  ground  .  .  238 

Object  in  storing  large  quantities  of  clay;  Drying  grounds  and  shed; 
Manner  of  pulverizing  the  clay  ......  .  .  .  .  239 

Proper  selection  of  machinery;  Advice  to  one  about  to  undertake  the 
making  of  brick  by  the  dry  process;  Importance  of  storing  a  large 
quantity  of  clay  in  sheds  .  .-  •  '•'".•  •  •  >  •  •  •  24° 

Dry-clay  pulverizers  described       :    .!        *v      .     •    .         .         .         .         .  241 

Late  improvements  in  machines  for  moulding  clay  by  the  dry  process.  242 

Dry-clay  brick  machines;  Strength  of  the  dry  press;  Difficulties  machine- 
men  have  to  contend  with  .  .  *  .  .  .  .  .  243 

Drying  of  dry-clay  brick;  Drying  in  the  opefi  air;  Drying  furnaces;  Use 
of  steam  for  drying  purposes  .  .  .  .  .  .  .  244 

Burning  dry-clay  brick;  Setting  the  brick  in  the  kiln;  Description  of  a 
kiln  .  -  . 245 

Firing  dry-clay  brick;  The  great  object  in  the  early  stages  in  burning 
dry-clay  brick;  Explanation  of  the  "limit  of  the  water  shrinkage."  246 

4 '  Water  of  shrinking ' '  and  ' '  water  of  porosity. " 247 

Experiment  on  the  shrinking  power  of  clay;  "Point  of  greatest  density 
of  the  mass;"  Proportion  of  fuel  required  to  burn  a  kiln  of  dry-clay 
brick ;  Semi-plastic  brick  «  .  .  .  .  .  .  248 

Semi-plastic  brick  press,  described  and  illustrated         .        .         .         .  249 

CHAPTER  VIII. 

THE  MANUFACTURE   OF   PRESSED  AND   ORNAMENTAL  BRICK. 

Pressed  brick;  Composition  and  days'  work  of  a  hand-press  gang; 
Method  of  making  pressed  brick  by  hand 251 

Single  cast-iron  mould;  Importance  of  the  moulding  sand;  Drying  and 
pressing  the  brick;  Care  of  the  mould  lid  and  plate  of  the  press;  Man- 
ner of  setting  pressed  brick  in  the  kiln,  with  illustration  .  .  252 


xviii  CONTENTS. 


"Gluts"  for  pressed  brick;  Directions  by  Geo.  Carnell,  of  Philadelphia, 
Pa.,  for  making  fine  front-brick  .  ......  254 

Paper  by  Mr.  William  Roberts,  of  Trenton,  N.  J.,  on  "Press  Brick: 
Their  Manufacture  and  Use."  ........  255 

Selecting  and  preparing  the  clays — "Weathering."         .         .         .         .257 

Main  points  to  be  considered  in  combining  materials  for  pressed  brick.  258 

Benefits  gained  by  weathering  clay          .......  259 

Loss  by  weathering;  Moulding  the  gluts 260 

One  of  the  first  qualities  required  in  a  good  press  brick;  Making  brick 
with  a  soft-clay  machine;  Quality  of  the  sand  required  to  be  used  in 
making  brick  with  a  soft-clay  machine  .  .  .  .  .  .261 

Moulding  brick  in  a  stiff-clay  machine;  Drying  the  "gluts"  before  re- 
pressing   262 

Re-pressing;   Burning  pressed  brick 263 

Advantages  gained  by  the  careful  study  and  improvemeats  in  the  burn- 
ing of  the  brick;  Reason  why  the  proper  burning  of  the  brick  is  of 
vital  importance  ....  .....  264 

Setting  the  brick;  Setting  in  the  open-top  or  Dutch  kiln;  Time  required 
for  the  proper  burning  of  a  kiln  of  pressed  brick  ....  265 

Re-burning  of  brick 266 

Importance  of  the  proper  burning  of  brick  to  the  Trenton,  N.  J.,  manu- 
facturer; Kilns  used  in  Trenton,  N.  J. ;  Time  occupied  in  burning  a 
kiln  in  Trenton,  N.  J 267 

Cost  of  fuel  for  burning  brick  in  Trenton,  N.  J. ;  Mr.  C.  W.  Raymond, 
on  "Pressed  and  Ornamental  Brick;"  Advisability  of  having  certain 
days  on  which  to  "strike  out"  brick  for  re-pressing  .  .  .  268 

Actual  test  of  the  material  for  pressed  brick  by  a  practical  burner;  Man- 
ner of  preparing  the  clay  and  striking  out  the  brick  for  making 
pressed  brick ..'...  269 

Pugging  process;  Sanding  the  moulds;  Tempering  the  clay;  What  ma- 
chine is  best  adapted  for  re-pressed  brick?  Importance  of  the  re-press.  270 

Care  of  the  press;  Pressure  required  to  re-press  a  brick;  Importance  of 
drying  sheds 271 

Arrangement  of  the  drying  shed;  Repressing  the  gluts;  Setting,  as  done 
by  the  Royal  Brick  Company,  of  Bridgeport,  Ohio  .  .  .  272 

Importance  of  burning  in  the  production  of  pressed  and  ornamental 
brick;  Invested  capital  represented  by  a  kiln  of  brick  ready  to  fire.  273 

No  fixed  rule  applicable  to  the  kind  of  fuel  required  and  amount  thereof 
consumed;  Main  point  in  burning  pressed  brick;  Opening  the  kiln; 
Sorting  the  brick  .  .  .  . 274 

Importance  of  preserving  the  faces  of  the  brick;  Danger  of  the  produc- 
tion of  large  numbers  of  pressed  brick  per  day;  Number  of  pressed 
brick  produced  per  day  in  Philadelphia  .  .  .  •'•'-..  .275 

Quality  of  first  importance  in  pressed  brick      .        .        .         .         .         .  276 

Ornamental  brick;  Perfection  press  invented  and  patented  by  Mr.  C. 
W.  Raymond,  of  Dayton,  Ohio,  described  and  illustrated  .  .  .277 


CONTENTS.  xix 

PAGE 

Manufacture  of  ornamental  brick  and  tiles  by  the  stiff  mud  process; 
Various  appliances  for  making  ornamental  work;  Substances  em- 
ployed to  prevent  the  matrix  adhering  to  the  clay  .  .  ...  280 

Preparation  of  the  clay  for  ornamental  work;  Use  of  pulverized  brick 
or  "  grog  "  for  preventing  shrinkage  .......  281 

Panel  re-press  manufactured  by  the  Frey-Sheckler  Co.,  described  and 
illustrated 282 

Eagle  Double  Mould  Re-press,  described  and  illustrated          .         .         .  283 

CHAPTER    IX. 

KILNS. 

Temporary  kilns;  Kiln  of  Mr.  Wm.  H.  Brush,  of  Buffalo,  New  York, 
with  detailed  description  and  illustrations  .  '  .  .  .  .  .  284 

Up  and  down  draft  kilns;  Invention  of  Mr.  Willis  N.  Graves,  of 
St.  Louis,  Mo.,  of  brick  kiln,  with  detailed  description  and  illustra- 
tions .............  287 

Continuous  kilns;  Principle  of  continuous  kiln;  The  railway  kiln         .  291 

The  Hoffman  kiln;  Drawbacks  to  the  use  of  Hoffman's  and  other  con- 
tinuous kilns,  especially  in  the  United  States  .'  '.  .  .  .  292 

Sizes  of  the  English  and  German  brick;  Comparison  of  the  quantity  of 
coal  required  for  burning  brick  in  Europe  and  in  the  United  States; 
Reason  why  all  endeavors  to  reduce  the  quantity  and  cost  of  fuel 
have  originated  in  Europe  ,  ,  •  .  .  .  .  .  .  .  294 

Modification  of  the  Hoffman  kiln  by  Mr.  Guthrie,  of  Manchester, 
England;  Adaptation  of  the  Hoffman  kiln  for  the  United  States  .  295 

Firing  the  Hoffman  kiln     .  - 296 

Impracticability  of  burning  some  forms  of  material  in  the  old-fashioned 
open  kiln;  The  Dueberg  kiln,  a  modification  of  the  Hoffman  kiln; 
The  Mendheim  kiln  V  .  .  .  .  .  .  .  .  .  297 

Regenerative  kilns;  Objects  of  all  late  improvements  in  the  regenera- 
tive kilns,  and  how  best  effected  .  .  .  .  . ;'.;  .  .  .  298 

The  Dunnachie  kiln,  described  and  illustrated          .        .  -•'      .         .         .  299 

Permanent  kiln  roofs;  Kiln  roof  invented  by  Mr.  Thomas  F.  Adams, 
of  Philadelphia,  Pa.,  with  detailed  description  and  illustrations  .  303 

CHAPTER    X. 

THE    MANUFACTURE    OF  FIRE-BRICK;    SILICA   FIRE-BRICK; 

CARBON  FIRE-BRICK  FOR  FURNACES ;  GLASS-POTS 

AND  GAS-RETORTS. 

Essential  qualities  of  a  good  fire-brick;  Different  furnaces,  and  different 
parts  of  the  furnace,  should  be  treated  differently  .  ;  .  .  3°6 

Abrasive  and  corrosive  power  of  coal  dust  and  ashes;  Properties  of  a 
good  brick;  Cause  of  shrinkage;  Classification  of  refractory  materials.  307 


XX  CONTENTS. 


Causes  to  which  the  irregular  wearing  in  furnace  roofs  may  be  due; 
Tendency  of  silicious  brick  to  expand  under  the  influence  of  intense 
heat 308 

Crushing  weight  of  an  ordinary  fire-brick;  Fire-brick  for  the  various 
parts  of  the  structure;  Considerations  to  be  regarded  in  discussing 
the  manufacture  of  a  refractory  material  which  is  to  be  used  in  a 
given  locality 309 

Material  used  in  Belgium  for  blast  furnace  brick;  Necessity  of  study- 
ing the  way  in  which  the  material  tempers;  Care  of  fire-brick  before 
being  used  in  the  furnace 310 

Properties  of  fire-brick  of  good  quality  when  broken;  Setting  of  fire- 
brick forming  the  lining  of  chimney  shafts;  Slow,  progressive  firing 
required  for  a  properly  burned  brick ;  Color  of  well-manufactured 
fire-brick;  Chemical  changes  which  take  place  in  the  burning  .  .311 

Paleness  of  color  of  a  fire-brick  not  at  all  times  a  safe  indication  of  the 
absence  of  iron ;  Clay  for  laying  fire-brick  .  .  .  .  .  .312 

Fire-brick  shapes  carried  in  stock  by  Messrs.  Fredericks,  Monroe  & 
Co.,  Farrandsville,  Pa.,  described  and  illustrated;  Refractory  brick 
work  of  blast  furnaces,  and  its  preservation;  Diversity  of  objects  the 
blast  furnace  has  to  serve  .  >  ..''  ..»•'  .  -.  .  .  .  .  313 

Nine-inch  shapes  of  fire-brick,  illustrated          .         .        .        ."      .    ;   ..314 

M'Keuzie  cupola  shapes,  illustrated;    Cupola  blocks,   illustrated.         .  315 

Increase  in  the  daily  output  of  pig-iron;  Influence  exerted  by  a  blast- 
furnace upon  the  refractory  material;  No  material  known  which  can 
successfully  withstand  the  dissolving  influences  of  a  blast-furnace  .316 

Blast-furnace  linings,  illustrated          ..",.•..       .         .        .-       .         .  317 

Blast-furnace  bottoms,  illustrated         .        .        .        .        .        ...  318 

Best  means  of  preserving  the  walls  of  blast-furnaces;  The  carbon  brick.  319 

Siemens  heating-furnace  blocks,  illustrated  .         »         .,  .    _  .         .  320 

Cause  of  the  rapid  wear  of  the  brick  work  of  the  stacks  of  blast-furnaces; 
Formation  of  cyanogen  in  the  blast-furnace  .  .  ...  .321 

Siemens  regenerator  tile  and  brick,  illustrated;  Glass-furnace  brick, 
illustrated .  ..<.-.  .  322 

Power  of  cyanogen  to  withdraw  alkalies  from  the  refractory  brick;  Lo- 
comotive fire-box  arches,  illustrated  .  .  .  .  .  323 

Destruction  of  coke  ovens  in  consequence  of  the  development  of 
chlorine  .  .  .  ...  .  .  .....  324 

Salts  soluble  in  water  contained  in  the  different  cokes  used  in  blast- 
furnaces; Coke  oven  brick  and  tile,  illustrated;  Feed-hole  blocks,  illus- 
trated  325 

Influence  of  salts  upon  the  refractory  brick  of  the  walls  of  blast- 
furnaces; Destruction  of  fire-brick  by  the  gradually  augmenting  sep- 
aration of  carbon;  Properties  of  carbon-brick  made  without  the  addi- 
tion of  clay,  etc.;  Carbon  deposits  in  fire-brick  .  .  i  .  326 

Bursting  of  fire-brick  from  the  formation  of  carbon  deposits  on  particles 
of  iron  derived  from  pyrites;  Rolling-mill  tiles,  illustrated  .  .  327 


CONTENTS.  xxi 

PAGE 

Explanation  of  the  bursting  of  fire-brick;  Cause  of  the  formation  of  de- 

posits of  carbon  in  the  brick  linings  of  blast-furnaces          .       ^         .  328 
Tile  for  fire-places,  illustrated          ......         .         .  329 

Fire-brick,  special  shapes   manufactured  by  The  Harbison  &  Walker 

Co.,  of  Pittsburgh,  Pa.,  illustrated;  Sorting  fire-brick     ....  330 

Plan  of  Siemens  steel  furnace,  illustrated          ......  331 

Charge  for  a  No.  i  brick;  Materials  used  in  No.  2  and  No.  3  brick          .  332 
Siemens    regenerator    blocks,    illustrated;     Siemens     heating-furnace 

blocks,  illustrated          ........         .        .  333 

Arch  tile  for  door  of  furnace,  illustrated;  Swindell's  and  McKenna's 

patent  checkers,  illustrated;  Bessemer  converter  tuyere,  illustrated; 

Sleeves  for  stopper  rod,  illustrated;  Ladle  nozzle,  illustrated  .  .  334 
Effects  of  a  nail,  bolt  or  some  stray  piece  of  iron  getting  into  a  kiln  of 

brick;  Section  of  iron  cupola,  illustrated          .         .         .....  335 

Explanation  of  the  blackening  of  the  faces  of  the  arch-brick  and  those 

most  exposed  to  the  direct  heat  of  the  fires;  Blocks,  tiles  and  special 

pieces,  and  their  manufacture;  Cupola  lining-brick,  illustrated  .  336 
Blast-furnace  crucible  and  bosh,  illustrated  ,  .  .  .  .  337 
Blast-furnace  bottom  blocks,  illustrated  ...  ,  .  .  .  .  338 
Boiler  tiles,  illustrated;  The  Harbison  &  Walker  Co.  on  the  difference 

in  the  nature  of  the  service  required  of  the  brick  in  the  different  parts 

of  the  furnace          .         .         .        .      .*    '     .         .         .         .        .         .  339 

Stove  lining  and  grate  backs,  illustrated         .         .         .         .         .         .  340 

Railroad  specialties,  illustrated          ,        .    .  :  .'        .         .         .         .       .  .  341 

Great  care  required  in  the  manufacture  of  blocks  and  tiles;  Coke-oven 

work,  illustrated          .-         .         .   •      .          .          .         .         .         .         .  342 

Tiles  and  blocks  necessary  in  setting  a  bench  of  fire-clay  retorts  in  gas 

works,  illustrated;  Defect  in  making  large  tiles  or  blocks  .  .  .  343 
Cover  tile  for  steel  coke-holders,  illustrated;  Floor  tile,  illustrated;  Rab- 

beted tile  for  greenhouses,  flues,  etc.,  illustrated;  Slabs  and  steam- 

boat  bridge-wall  tile,  illustrated  ;     Machine   for   making    tiles  and 

blocks          .         .         ...         .         .          .         ...         .         .  344 

Fire-brick  works  and  their  construction;   Frequent  absence  of  arrange- 
ment in  plants;  First  subject  requiring  attention  in  the  erection  of  a  new 

works        .         ...        ...         .         .         .         .         .         .         .  345 

Plans  for  a  new  works          .  .         .         .         .         .         .         .         .  346 

Boilers;  Engine  power;  Wear  and  tear  of  engines;  Dry-pans  with  under 

or  over-gearing;  Objections  to  under-geared  mills  .  .  .  .  347 
Elevators  and  wet-pan;  Description  of  the  clay-belt  .  .  .  .  348 
Another  way  of  conveying  the  clay  from  pan  to  tables;  Main  building  or 

factory  and  its  arrangement;  Covering  for  the  roof  ...  .  349 
Steam  drying  floors;  Methods  of  counteracting  the  expansion  and  con- 

traction of  iron  pipes;  Description  of  a  steam  dry-floor  used  in  Eng- 

land         .         .         .        .        .        .        .        .        ...        .        .  350 

Attempts  to  adopt  this  floor  in  this   country          .         .        .         .        .  351 


UNIVERSITY 


xxii  CONTENTS. 


PAGE 


Advantages  of  this  steam  dry-floor 352 

Objections  to  this  plan  of  steam  drying;  Plan  generally  adopted  in  the 
erection  of  fire-brick  works 353 

Turley  &  Beyerly's  dry-floor;  Hot  air  drying-floor  in  use  by  the  Glen- 
boig  Union  Fire-Clay  Co.,  Limited,  of  Glasgow,  Scotland,  described 
and  illustrated 354 

Construction  of  hot  floors  in  use  in  some  of  the  older  fire-brick  works  in 
Ohio  and  Pennsylvania 356 

Conveying  fire-clay;  Clay  mine  of  the  Union  Mining  Company,  Mount 
Savage,  Md.,  and  its  management 357 

Winding  drums  and  dump  cars .  "     .  359 

Fire-brick  manufacture;  Desirability  of  a  practical  and  theoretical 
knowledge  of  the  business  by  the  proprietor  or  manager  .  .  360 

Branches  of  science  the  manager  should  become  acquainted  with.         .  361 

Basis  of  success  in  the  manufacture  of  fire-brick;  Storing,  weathering 
and  elutriating  fire-clay 362 

Only  object  in  storing  large  quantities  of  fire-clay;  Influence  of  the 
weather  in  ridding  clay  of  impurities;  Clays  which  should  and  which 
should  not  be  weathered.  .  .  .  .  .  .  .  .  .  363 

Improvement  of  fire-clays  by  elutriation;  Calcining;  "Chamotte"  or 
cement  and  its  qualities.  .  .  .  .  .  .  .  .  .  J  .  364 

Proportion  of  calcined  clay  or  chamotte  used;  Methods  of  preparing 
clay  for  calcining;  Calcining  kilns.  .  .  .  V  .  .  .  .  365 

"Lean  materials;"  Object  of  mixing  lean  material  with  the  clay;  Con- 
stitution of  the  mixture ;"  .  .  .  366 

Preparation  of  the  material  for  the  chamotte;  Proportion  in  which  the 
burnt  clay  or  the  substitute  for  it  is  mixed  with  the  crude  clays.  .  367 

Mixing  fire-clays;  The  refractory  nature  of  the  material  to  be  produced 
dependent  upon  the  quantity  and  quality  of  the  mixture;  The  Belgian 
method;  Usual  quantities  of  mixture  for  brick.  .  ...  .  368 

Use  of  coke  as  a  substitute  for  graphite;  Mixtures  made  by  mechanical 
means  and  by  human  labor;  Rates  of  expansion  and  contraction  of 
mixtures  and  of  fire-brick;  Devices  used  in  several  works  to  counter- 
act expansion  and  contraction.  ........  369 

Methods  of  measuring  the  proportion  of  each  factor  of  the  mixture; 
Washing  the  clay;  Washing  machine;  Grinding  and  tempering.  .  370 

How  to  obtain  complete  homogeneity  in  the  interior  of  the  brick,  and 
the  utmost  mechanical  strength;  Necessity  of  the  most  careful  and 
thorough  working  of  the  mass;  Unsuccessful  attempts  to  grind  hard 
clays  by  various  methods.  .  .  .*  .  .  .  .  .  •  371 

Methods  of  grinding  and  tempering;  Methods  in  use  in  America;  The 
wet-pan  method  and  its  advantages  .  .  .-  .  .  .  •  372 

Special  style  of  pan  used  by  the  Union  Mining  Co.,  of  Mount  Savage, 
Md.;  Grinding  and  preparing  fire-clay  by  the  dry-pan  and  pug-mill 
mixer  combined  .  ...  .-.;..  .  .  .  .  .  373 


CONTENTS.  xxiii 


Process  of  grinding  and  tempering  much  in  favor  in  the  older  river 
works  of  Jefferson  County,  Ohio,  and  at  Mineral  Point  and  Hayden- 
ville,  Ohio 374 

Moulding  and  pressing;  The  English  method;  Process  employed  in  the 
United  States;  Object  of  pressing 375 

Hand-pressing  and  steam-pressing;  Method  in  use  in  the  fire-brick  fac- 
tories of  St.  Louis,  Mo.  .  .  .  .  .  .  .  ;''.•_'••  .  376 

Notion  that  fire-brick  cannot  be  made  except  by  hand-moulding;  Un- 
successful attempt  in  the  North  of  England  to  produce  fire-brick  by 
machinery ;  Defect  of  machine-made  brick ;  English  method  of 
moulding  without  pressing  .........  377 

Cause  of  the  irregularity  in  re-pressing     .         .         .        .        ...  378 

Method  of  moulding  in  the  St.  Louis,  Mo.,  district;  Method  of  making 
fire-brick  in  the  county  of  Durham  and  in  Northumberland,  near 
Newcastle-on-Tyne,  in  England,  described  by  Mr.  Thomas  Pickering, 
of  Chicago,  111 -. :  .  379 

Drying  and  tempering;  Temperature  at  which  drying  is  commenced; 
Gradual  rise  in  the  temperature;  Importance  of  a  long  period  of 
tempering  .  .  .  ~  V ,  .  ;  -.  .  .  .  .  .  .  380 

Drying  large  pieces  in  Belgium;  Drying  of  fire-brick  in  the  United 
States;  Best  way  to  obtain  a  high-grade  of  fire-brick  ....  381 

Air-drying;  Expeditious  method  of  drying  required  in  the  manufacture 
of  fire-brick  on  a  large  scale  by  the  soft-mud  process.  .  .  .  382 

Burning;  Setting  the  brick  in  the  kiln;  Most  appropriate  form  of  kiln; 
Storage  of  fire-brick  .  .  .  .  > 383 

Calcine  kilns,  described  and  illustrated 384 

Silica  fire-brick;  Discovery  of  the  use  of  "  Dinas."          ....  386 

Duration  of  "  Dinas  "  or  silica  brick  in  very  high  and  long  continued 
heats;  One  of  the  troubles  of  clay  brick  which  silica  brick  escapes; 
Use  of  silica  brick  in  the  construction  of  open-hearth  steel  and  glass 
furnaces  in  the  United  States;  Expansion  of  silica  brick  .  .  .  387 

Provisions  for  expansion ;  Rules  for  the  users  of  silica  brick;  Appear- 
ance of  "  Dinas "  brick 388 

Occurrence  of  the  material  from  which  silica  brick  is  made;  Composi- 
tion of  "Dinas"  clay;  Manufacture  of  "  Dinas"  brick  .  .  .  389 

Firms  in  the  United  States  engaged  in  the  manufacture  of  silica  brick; 
Analysis  of  one  of  the  "  Star  Silica  "  brick 392 

Adoption  of  the  Dunnachie  continuous  regenerative  gas  kiln  for  burn- 
ing silica  brick;  Composition  of  silica  brick  made  by  Messrs.  J. 
Gray  son,  Lowood  &  Co. 393 

Carbon  fire-brick  for  furnaces;  Material  for  these  brick;  Burning  the 
brick;  Price  of  the  brick  ...  .  • 394 

Difficulties  encountered  in  placing  the  brick  in  position;  Glass  pots; 
American  and  German  clays  suitable  for  large  glass  pots  .  .  .  395 

Preparation  of  the  clay  for  glass  pots;  Different  kinds  of  pots  used        .  396 


xxiv  CONTENTS. 


Making  and  drying  the  pots;  Mode  of  shipping  the  pots        .         .         .  397 
Annealing  furnaces;  Removal  of  the  pots  from  the  annealing  oven  to 
the  main  furnace;  Material   for  the  arches  and  walls  of  large  glass 
ovens         .............  398 

Gas  retorts,  described  and  illustrated 399 

Weight  and  sizes  of  gas  retorts 401 

CHAPTER    XI. 

THE  MANUFACTURE  OF  ENAMELED  BRICK. 

General  remarks;  The  art  of  enameling  brick  older  than  recorded  his- 
tory; Its  introduction  into  Spain  and  Western  Europe  by  the  Moors; 
The  Alhambra  Palace  at  Granada,  in  Spain;  Revival  of  the  art  in 
France,  Continental  Europe  and  England,  and  its  subsequent  loss; 
Recent  revival  of  the  manufacture  of  enameled  brick  in  England.  402 

Lack  of  specific  knowledge  regarding  the  details  of  the  art  in  America; 
Decoration  of  the  brick  of  the  walls  of  Babylon  before  they  were 
burned;  Loss  of  time  and  injuries  to  the  brick  by  first  burning,  then 
enameling,  and  then  burning  them  the  second  time;  Importance  for 
enamel  to  coincide  with  the  contraction  and  expansion  of  the  clay 
body  to  which  it  is  applied 403 

Character  of  the  constituents  which  form  the  enamel;  The  employe's  of 
manufacturers  of  enameled  brick  in  England  not  allowed  to  become 
conversant  with  all  the  details  which  relate  to  the  production  of  this 
class  of  wares  .  .  .> .  .  404 

Causes  of  losses  and  failures  in  the  manufacture  of  enameled  brick  in 
the  United  States;  Necessity  of  a  thorough  study  of  the  subject; 
Experimenting  with  the  various  enamels  .  .  .  .  .  .  405 

Drawbacks  and  difficulties  which  may  be  encountered;  The  clay;  Pre- 
paring the  clay 406 

Making  the  brick;  Hand-made  brick  chiefly  used  in  England;  Size  of 
the  mould;  Care  to  be  exercised  in  employing  machinery;  Best  lubri- 
cants for  the  brickmaking  machinery  used;  Adjustment  of  the  die 
of  the  brick  machine  .  .  .  .  .  .  ...  .  407 

No  reason  why  machine-made  brick  should  not  fully  equal  those  made 
by  hand;  Floor  upon  which  the  brick  are  placed  to  harden;  Injury 
from  the  oxidation  of  iron  plates;  The  floor  and  the  importance  of 
heating  it;  Utilization  of  the  exhaust  steam  from  the  engine;  Use  of 
live  steam  .  .  .  .  .  .  J  .  *  i  t  .  408 

A  good  and  well-tested  system  in  present  use;  Importance  of  the  floor 
being  level  and  free  from  hollows  .  .  -.,  .  .  .  409 

Size  of  the  floor  quarries;  Supply  of  steam;  Desirability  of  laying  the 
floor  in  sections;  Time  required  for  drying  brick  upon  the  floor; 
Another  plan  of  constructing  a  floor 410 


CONTENTS.  xxv 


Pressing  the  brick  and  presses  used  for  the  purpose          .         .        .         .411 

Transport  of  the  pressed  brick  to  a  drying  room  provided  with  an 
arrangement  of  rack  and  pallets;  Enameling;  Polishing  the  face  or 
head  to  which  the  enamel  is  to  be  applied;  Manipulation  of  hand- 
made brick  ............  412 

Composition  of  the  various  glazes,  "bodies"  and  stains,  and  manner 
of  their  application  ..........  413 

First  body  used;  Manner  of  making  it 415 

Instructions  for  applying  the  dips;  Placing  the  brick  in  the  kiln  or 
oven;  Firing  the  kiln  .  .  .  .  .  .  ...  .  416 

Mixing  the  slips  and  bodies  with  clean  cold  water;  Weight  of  i  pint  of 
each  dip;  Explanations;  What  is  meant  by  "mix  for  use;"  Improve- 
ment in  the  buff  body  '.''..'.  .  .  .  417 

What  is  meant  by  "fire  hard  and  grind;"  Manner  of  preventing  the 
color  and  stain  from  sticking  to  the  seggar,  etc. ;  Grinding  and  dry- 
ing the  color  and  stain;  Mixing  the  colors  ......  418 

What  is  meant  by  "  calcining;  "  Necessity  of  obtaining  correct  weights 
of  quantities  used;  Where  the  materials  used  may  be  obtained;  Set- 
ting the  enameled  brick  in  the  kiln;  Conveying  the  brick  to  the  kiln.  419 

Care  should  be  taken  to  protect  the  enameled  faces  of  the  brick  from 
the  action  of  the  flames  as  they  pass  through  the  kiln;  Manner  of 
setting  enameled  brick  in  England;  Kilns;  The  method  of  burning 
enameled  brick  with  dead  heat  no  longer  in  vogue  ....  420 

Firing;  Steaming  or  water-smokiug  of  enameled  brick;  Defects  engen- 
dered by  a  too  quick  drying  off  of  tire  moisture;  Admission  of  air 
during  the  water-smoking  . ' 421 

Gradual  increase  in  the  heat;  Shape  of  the  test-proofs  used;  Examina- 
tion of  the  test-proofs  for  the  purpose  of  regulating  the  firing; 
Cooling;  No  aid  to  be  given  to  the  cooling  process  ....  422 

Caution  to  be  exercised  when  opening  holes  in  the  top  of  the  arch 
of  the  kilns;  Drawing  all  the  heat  from  the  kiln  without  injuring  the 
enamel -brick;  Sorting  the  brick  into  three  classes;  Where  the  enamels, 
glazes  and  colors  used  may  be  obtained;  Enameling  slate  waste-brick; 
Process  and  recipes.  .  ,  .  .  .  .  .  .  .  .  423 

Recipes  of  body  and  white  glaze 424 

CHAPTER  XII. 
THE  MANUFACTURE  OF  SEWER-PIPE. 

Selection  of  clay  for  sewer-pipe;  Methods  of  making  sewer-pipe  in  the 
State  of  Ohio;  The  river  process  and  the  Akron  process;  Constitution 
of  the  pipe-press.  . 425 

Dimensions  of  the  presses  used;  Differences  in  the  Akron  process  and 
the  river  process;  Grinding  machinery  of  the  Akron  district.  .  .  426 

Difference  between  the  Cincinnati  Standard  pipe  and  ordinary  pipe; 


XXVI  CONTENTS. 


Constitution  of  a  gang  necessary  to  run  a  press;  Press  in  use  at  the 
Eliottsville  works;  Capacity  of  a  press;  Heat  used  in  sewer-pipe 
burning;  Quantity  of  salt  required  to  a  kiln;  Process  of  glazing.  .  427 

Philosophy  of  the  formation  of  the  glaze;  What  the  glaze  produced  upon 
earthenware  pipes  is;  Manner  of  producing  the  brown  color  on  drain- 
pipes. .........  .  .  .  428 

Curves,  elbows,  S-traps,  T-pieces,  X,  Y  and  U  pieces,  etc. ;  Clay  used  for 
the  "river-pipe"  manufactured  in  Ohio;  Fracture  of  a  piece  of  river- 
pipe;  Strength  of  this  pipe;  Precaution  to  be  observed  in  burning; 
Effect  of  iron  in  Kittanning  clays .  .  429 

Color  of  river-pipe  and  of  Akron  and  Columbus  pipe;  Grinding  and  tem- 
pering of  the  clay;  Worst  trouble  of  the  Akron  pipe.  .  .  .  430 

Kilns  used;  Character  of  Akron  sewer-pipe  ware;  Inability  of  the  Akron 
works  to  make  the  Cincinnati  Standard  pipe;  Monopoly  of  the  Akron 
works  of  the  patent  device  for  making  curves,  elbows,  S's  and  traps.  431 

Definite  signification  of  the  word  "vitrified;"  Description  of  the  manu- 
facture of  sewer-pipe  by  the  Delaware  Terra-Cotta  Co.,  of  Wilming- 
ton, Del.,  by  Frederick  H.  Robinson;  Material  of  which  the  pipes  are 
made.  .  .  .  .  .  .  .  .  ,  •  .-  432 

Raising  the  clay  and  compressing  it  in  the  mould.         .        .__ .         .  433 

Trimming  and  drying  the  pipes;  Manner  of  making  branches  and  traps; 
The  kilns;  Filling  the  kiln;  Introduction  of  salt;  Time  required  for 
firing  up  and  burning.  ,,.-.  .  .  .  •  .  .  .  .  ..  .  .  434 

Making  curved  earthenware  pipes  of  equal  thickness  on  all  sides;  Ma- 
chine of  Mr.  Horace  B.  Camp,  of  Cuyahoga  Falls,  Ohio,  for  the  forma- 
tion of  curves,  elbows  and  traps,  described  and  illustrated.  .  .  435 

Machines  for  forming  sockets  on  curved  earthenware  pipes;  Machine 
for  this  purpose  invented  by  Mr.  Horace  B.  Camp,  of  Cuyahoga  Falls, 
Ohio,  described  and  illustrated.  , 437 

Machine  for  cutting  sewer-pipe  rings,  described  and  illustrated       .         .  440 

Contrivance  for  preventing  the  displacement  of  drain-pipes  in  the  kiln, 
invented  by  Mr.  John  Murtagh,  of  Boston,  Mass.,  described  and  illus- 
trated. .  .  .-.;..  .  .  .-'•'.  ..  .  .  .  442 

Barrow  for  wheeling  sewer-pipe  and  drain -pipe,  described  and  illustrated; 
Table  showing  diameter  and  thickness  and  average  weight  per  foot  of 
salt-glazed  vitrified  sewer-pipe,  usually  kept  in  stock.  .  .  .  444 

Capacity  of  sewer-pipe  for  resisting  pressure;  Manner  of  finding  the 
pressure  in  pounds  per  square  inch  of  a  column  of  water;  Form  of 
sewer-pipe .  .'  '  .  .  .  .  ,  .  .  .445 

CHAPTER   XIII. 
THE  MANUFACTURE  OF  DRAIN  TILE. 

Form  and  size  of  drain  tile  for  agricultural  underground  drains;  Table 
of  prices  as  F.  O.  B.  at  factory,  say  in  central  Ohio;  Mining  and  mix- 
ing the  clay 446 


CONTENTS.  XXvii 

PAGE 

Selection  of  clay  for  drain  tile;  Mr.  John  G.  Wagner,  of  Covington,  Ky., 
on  preparing  and  handling  clay  for  tile;  Location  of  the  factory; 
Starting  in  a  small  way;  Manner  of  systematizing  the  work.  .  .  447 

Enlarging  the  works;  Different  method  of  getting  in  the  clay;  Manner 
of  preserving  the  state  of  moisture  of  the  clay  in  the  bank;  Wintering 
of  clay.  ...  .  .  .  ......  448 

Mixing  clays  with  crushed-brick  or  tile  or  sand;  Mr.  E.  M.  Pike,  of 
Chenoa,  111.,  on  drain  tile:  its  manufacture  and  use;  Origin  of  drain 
tile  in  the  first  century  of  the  Christian  era;  Columella  on  the  culti- 
vation of  the  soil,  and  on  drainage.  .  .  ..  ..  .  ..  .  449 

Use  by  the  Romans  of  earthen  pipe  to  convey  water  to  cisterns;  The 
oldest  reference  to  under-drains  for  agricultural  purposes;  First  strike 
that  ever  occurred  on  a  building  or  in  a  brick-yard.  ,  .  .  .  450 

Form  and  size  of  drain  tile;  Benefit  derived  from  drain  tile;  Temperature 
of  drained  soil.  .  .  .  .  .  V  V  .  -  .  .  451 

Tile  drainage  a  safeguard  against  drouth;  How  the  "white  man  brings 
rain;"  Former  notion  that  tile  drainage  was  conducive  to  floods; 
Manufacture  of  tiles,  and  extent  of  drainage  in  Illinois.  .  .  .  452 

Manufacture  of  tiles  in  other  Western  States  and  in  the  South;  Advant- 
ages of  drainage  from  a  sanitary  point  of  view;  Practical,  rather  than 
theoretical,  analysis  of  clay.  -,.  .  ,  .  .  .  .  .  .  453 

Capital  created  by  farm  drainage;  Lack  of  available  knowledge  pertain- 
ing to  the  clay  business;  Secrecy  maintained  at  the  Royal  potteries  in 
England 454 

Elevating  devices  for  brick  and  tile;  Endless  elevator,  described  and  il- 
lustrated; Platform  elevators;  Drying  drain  tile;  Causes  of  the  cracking 
of  the  tile;  Steam  drying;  The  Wolff  and  similar  forms  of  dryers.  .  455 

Temperature  for  drying.         .     '  -  .          .          .         .          .          .  456 

Drying  in  open  sheds;  Burning  drain  tile;  Setting  the  tile  in  the  kiln.  457 

Methods  of  nesting  the  tile;  Firing  the  tile;  Desirability  of  not  pushing 
the  burning  too  rapidly;  Caution  to  be  observed  not  to  increase  the 
heat  to  the  actual  fluxing  point .  .  458 

Proper  management  of  open-top  kilns.         .         .         ,         .         .         .  459 

Burning  drain  tile  with  natural  gas;  Kiln  selected  for  describing  the 
process.  .  .  ,  .  .  .  .  ....  .  .  460 

Tile-making  machines;  Improved  Centennial  machine,  described  and 
illustrated.  ...  .  .  .  ;  .  .  .  .  461 

Brose  Patent  Tile  Table  for  cutting  and  handling  tile,  described  and 
illustrated.  .  .  .  .  .  .  .-  •  '.*;V.V  ...  •  •  463 

Leach  Patent  Table,  described   and  illustrated 464 

Dodd  Carrier  for  horizontal  tile  machines,  described  and  illustrated.  465 


xxviii  CONTENTS. 

CHAPTER  XIV. 
THE  MANUFACTURE  OF  ARCHITECTURAL  TERRA-COTTA. 

PAGE 

Early  use  of  terra-cotta;  Discoveries  in  an  old  well  at  the  Porta  Latina, 
at  Rome;  First  application  of  the  name  terra-cotta;  Lasting  qualities 
of  terra-cotta.  ...........  468 

Examination  of  a  piece  of  terra-cotta,  in  cold  weather,  under  a  magni- 
fying glass;  Beauty  of  color  of  terra-cotta;  Applicability  of  terra-cotta 
to  decoration;  Studio  of  a  modern  terra-cotta  factory;  Skill  required 
in  making  the  plaster  molds  to  fit  the  model;  Qualifications  required 
of  modelers 469 

Use  of  terra-cotta  for  decoration;  Endurance  of  terra-cotta;  Its  introduc- 
tion into  the  United  States,  and  early  experiments  with,  by  Mr. 
James  Renwick;  Introduction  of  English  methods  in  Chicago;  Plant 
of  the  Perth  Amboy  Terra-Cotta  Company  and  some  of  the  prominent 
buildings  for  which  it  has  furnished  terra-cotta  details;  Increase  in  the 
demand  for  architectural  terra-cotta.  ......  470 

Terra-cotta  work  in  the  United  States;  Production  of  pure  white  terra- 
cotta by  the  works  at  Long  Island  City;  Possibilities  in  the  production 
of  colored  terra-cotta;  Panels  and  gable  work  in  the  library  of  the 
University  of  Pennsylvania  and  the  Drexel  Institute,  Philadelphia,  Pa.  471 

Specimens  of  the  work  of  Messrs.  Stephens  &  Co.,  of  Philadelphia,  Pa., 
and  of  the  New  York  Architectural  Terra-Cotta  Company,  illustrated.  472 

Recent  material  prosperity  of  this  country  evidenced  by  its  street  archi- 
tecture. .  .  .  .-::.- V  .  .  478 

Division  into  two  classes  of  the  designs  of  buildings  which  are  dependent 
upon  terra- cotta  work  for  their  enrichment;  Ideas  of  architects  regard- 
ing the  use  of  burned  clay  in  other  forms  than  common  brick;  Impos- 
sibility of  reproducing  in  burnt  clay  the  exact  shade  of  color  of  stone.  479 

How  uniformity  of  color  in  terra-cotta  may  be  obtained;  What  the 
proper  use  of  terra-cotta  demands;  Necessity  of  remembering  the  plas- 
ticity and  shrinkage  of  the  material  when  making  designs  for  execu- 
tion in  terra-cotta.  ..........  480 

Various  treatments  of  surface  in  vogue;  Errors  in  construction  by  the 
use  of  terra-cotta;  Instances  of  bad  construction;  Disfigurement  of 
buildings  by  grimy  and  black  streaks.  ,  .  '  . '  .  .  .  ...  .481 

Color  of  terra  cotta;  Impossibility  of  its  absolute  uniformity  of  color; 
Production  of  an  ideal  brick  and  terra-cotta  structure;  A  terra-cotta 
factory  and  its  arrangement  for  the  different  varieties  of  work  .  .  482 

Amount  of  water  which  has  to  be  evaporated  in  drying.          .        .         .483 

Location  of  the  kilns  in  the  factory,  with  illustration      .        .  .  484 

Ventilation  and  protection  from  fire.          .        .        .        »        »        ;        .  485 

Treatment  of  clays  for  the  manufacture  of  architectural  terra-cotta; 
Reduction  of  the  natural  shrinkage  of  the  clays;  Mixtures  of  clay 
and  grit.  .  .  .  . 486 


CONTENTS.  xxix 


PAGE 


Method  of  finding  the  proportion  of  grit  suited  to  the  crude  clay  .         .  487 

Value  of  dipping  and  washing  for  terra-cotta  work;  Method  adopted 
by  Brnest  March  at  Charlottenburg;  Advantages  of  the  washing 
process  may  be  obtained  by  the  use  of  a  cylinder-crusher  and  stone- 
separator  for  plastic  clays,  and  of  a  pulverizer  for  clays  of  a  shaly 
quality;  Preparation  of  the  grit;  Various  methods  of  preparing  the 
batch  or  mixture,  with  illustrations 488 

Difference  of  opinion  as  to  what  kind  of  machinery  is  best  suited  for 
preparing  clays  and  mixtures  of  clays  for  terra-cotta  .  .  .  .491 

Kinds  of  clay  the  terra-cotta  maker  must  have;  Difference  in  the  value 
of  clay  when  manufactured  into  brick  and  into  terra-cotta  •  •  -  .  493 

Machines  required  to  furnish  an  effective  plant  for  the  manufacture  of 
terra-cotta;  Machines  adopted  by  Mr.  James  Taylor  .  .  «  .  494 

Six-stamp  mill  for  crushing  the  grit,  described  and  illustrated;  Clay 
mixers  .  .  .  .  .  .  .  .  '  .  .  .  -.  .  495 

Soaking  and  ripening  the  clay;  Tempering  the  stiff-mud;  Pugging  the 
clay 496 

Description  of  a  double  pug-mill;  Moulding  and  modeling  the  clay; 
Drying  boards  and  their  use,  described  and  illustrated  .  .  .  497 

Principle  of  the  incline  of  the  drying  board     .         .  -  *.  -      .        .         .  498 

Philosophy  of  the  drying  of  a  panel  of  clay-work  .         .         .         .  499 

Possibility  of  directing  natural  forces;  Constant  watchfulness  required 
for  successful  drying;  Drying  by  steam  .  .  .  ...  500 

Ventilation  and  heating  the  workshops,  as  well  as  drying  the  work 
made  in  that  portion  of  the  factory  by  the  kilns;  General  rules  to  be 
observed  in  drying  ..-.'..  .  .  .  .  .  501 

Warping  and  cracking  produced  by  unequal  drying;  Burning  terra- 
cotta; Muffle  terra-cotta  kilns  used  by  the  New  Jersey  companies, 
described  and  illustrated  •  '  . '  .  .  .  .  .  .  .  .  5°2 

Kilns  used  by  the  works  in  Boston,  described  and  illustrated          .         .  503 

Muffle  kilns  adopted  by  western  works,  and  by  the  Northwestern  Terra- 
Cotta  Company,  of  Chicago;  Kind  of  fuel  used  .  . ,  .  .  .  504 

Essential  qualifications  in  a  good  kiln;  Fuels  for  terra-cotta   .         .         .  505 

Application  of  the  heat  by  the  over-draft  system;  Time  required  for 
burning  terra-cotta;  Improvement  in  the  construction  of  terra-cotta 
kilns;  Invention  of  Mr.  Alfred  Hall,  of  Perth  Amboy,  N.  J.,  de- 
scribed and  illustrated  ..........  5°6 

Modeling  terra-cotta;  Process  of  manipulating  terra-cotta       .         .         .  508 

Modeling  material;  Manner  of  modeling  a  head 5°9 

CHAPTER   XV. 

ORNAMENTAL  TILES,  ETC. 

Claim  that  the  art  of  painting  was  divine  and  coeval  with  the  very  crea- 
tion of  man;  Ancient  records  kept  upon  clay  tablets  nothing  more 


XXX  CONTENTS. 

PAGE 

nor  less  than  tile  books;  Reasons  why  tiles  are  found  so  universally 
under  every  form  of  civilization  and  in  every  age          .         .         .         .511 

Demand  for  tiles  in  the  United  States;  Definition  of  a  tile;  Families  of 
tiles  and  their  subdivisions  .  .  .  .  .  .  .  .  .512 

The  Egyptians  the  oldest  tile  makers  we  have  any  historical  knowledge 
of;  Decoration  of  the  inner  doorway  of  the  pyramid  at  Lagarra  with 
glazed  tile,  described  and  illustrated  .  .  .  .  .  .  -513 

Tiles  in  the  brick  temple  of  Rameses  III.  built  1228  years  before  the 
Christian  era,  illustrated  .  .  .  .  .  .  .  .  .514 

Tiles  used  by  the  Egyptians  and  Assyrians  for  the  ornamentation  of 
walls,  illustrated;  Use  of  tiles  by  the  Jews;  Superiority  of  the  tiles 
made  by  the  Babylonians  and  Assyrians;  Novel  form  of  a  Babylonian 
tile,  illustrated  .  .  .  .  .  .  .  .  .  .  .515 

Tiles  of  Chaldea,  illustrated;  Execution  of  pictures  and  geometric  de- 
signs by  uniting  tiles,  in  Assyria,  illustrated  .  .  .  .  .516 

Colors  in  the  glazed  tiles;  Gorgeousness  of  the  tile-incrusted  buildings 
of  Assyria;  Use  of  tiles,  in  Babylon,  as  a  circulating  medium  .  .  517 

Tiles  of  the  Jews  and  Phoenicians;  Employment  of  tiles  by  the  Greeks, 
Etruscans  and  Romans  .  *  .  .  .  .  .  .  .  .  518 

Revival  of  the  art  of  tile  making  by  the  Mohammedans  in  the  East 
and  the  Monks  in  the  West;  Development  of  tile  making  in  the 
United  States;  Erection  of  a  tile  factory  by  Mr.  John  G.  Low  at 
Chelsea,  Mass.  .....  .  .  .  .  .  ...  519 

Gold  medal  won  by  Mr.  John  G.  Low  at  Crew,  England,  for  the  best 
collection  of  art  tiles  . .  .  521 

Specimens  of  art-tile  soda  fountains  made  by  Messrs.  J.  G.  and  G.  F. 
Low,  illustrated;  Other  firms  in  the  United  States  engaged  in  the 
manufacture  of  art  tiles;  Rapid  advancement  of  America  in  the  pro- 
duction of  printed,  inlaid  and  relief  tiles;  Art  tiles  at  the  Columbian 
Exposition,  in  1893;  Process  of  making  art  tiles  explained  by  Mr. 
Lawshe;  First  step  toward  making  tiles;  Mixing  the  chalk  and  flint.  522 

Mixing  with  water;  Squeezing  out  the  water;  Drying  and  breaking  up 
the  material;  Grinding  the  material  and  conveying  it  to  bins;  Stamp- 
ing machine  ............  523 

Mode  of  stamping;  Die  cutting;  Modeling         .         .        .        .  :      .         .  524 

Dipping  the  tiles .        .        .         .  525 

Firing  the  tile;  Placing  the  tiles  in  setters;  Disposition  of  the  setters  in 
the  kiln;  Mode  of  securing  a  perfect  disposition  of  the  "glost"  on  the 
face  of  the  tile;  Packing  and  inspection  of  the  tile;  Majority  of  the 
tiles  used  in  America  made  in  Trenton  and  Cincinnati;  Art  of  making 
large  tiles  in  one  solid  piece  a  New  Jersey  discovery  ....  526 

Prices  of  tiles;  Valuable  discovery  for  making  patent  tiles  by  Miss  Frye; 
Fortune  for  the  man  who  will  rediscover  the  lost  art  of  producing  the 
green,  blue  and  red  of  the  ancients  from  copper;  Screw-press  made  by 
Mr.  Peter  Wilkes,  of  Trenton,  N.  J.,  for  the  Trent  Tile  Co.,  described 
and  illustrated  .  .  ....  .  .  *  .  .  .  .  .  527 


CONTENTS.  xxxi 


Great  attention  paid  in  France  to  the  manufacture  of  glazed  and  enam- 
eled tiles;  Guiding  points  in  glazing  tiles       ......  528 

Preparation  of  glazes  free  from  lead,  and  the  mode  of  using  them  .        .  529 

Glazes  containing  lead 530 

Munich  process  of  manufacturing  colored  glaze  tiles;   Production  of 

colored  enamel 531 

Occurrence  of  lead-poisoning  in  the  manufacture  of  enameled  tiles  and 
its  prevention;  Remedies  for  lead-poisoning;  Manufacture  of  clay-dust 
tiles  having  surfaces  in  relief  or  intaglio;  Plan  of  a  tile  with  an  in- 
taglio figure  thereon,  illustrated;  Plan  of  a  tile  with  a  figure  in  relief 
thereon,  illustrated;  Cross-section  illustrating  the  manner  of  their  use;* 
Application  of  the  process  by  Mr.  Low,  the  inventor  of  it    .      •  -.'•        .  532 
Production  of  high  reliefs  .         .         .         .         .         .         .         ...  533 

Manner  of  obtaining  textures,  low  reliefs,  or  intaglios  of  natural  objects; 
Electrotypes  from  the  compressed  plates;  Use  of  a  diaphragm  of  Jap- 
anese paper,  or  other  material         .         ;  -:  >  .         .      -  .    "    .      -..'.        .  534 
Remarkable  sharpness  and  definition  of  texture  of  reliefs  made  from 
dust  clay  intaglios;  Mode  of  obtaining  in  tile  both  the  relief  and  in- 
taglio of  the  impression  in  the  clay-dust;  Want  of  a  good  method  of 
fixing  wall  tiles         .         .         .         .         .         .         •    '^  ,         .         .         .  535 

Mr.  Low's  method  of  forming  dovetailed  grooves  on  the  backs  of  tile; 
Manufacture  of  wet-clay  flooring  tiles;  Machine  invented  by  Mr. 
George  Elberg,  of  Columbus,  Ohio,  described  and  illustrated  .  .  536 

CHAPTER  XVI. 

THE   MANUFACTURE    OF    ROOFING-TILES;    THE   GLAZING   OF 
ROOFING-TILES. 

General  remarks;  Historical  data;  Profuseness  of  colors  employed  by 

the  Assyrians  in  the  decoration  of  brick        .         .         .        '.   •     .        .  542 
Tiles  used  by  the  Greeks  and  Romans,  illustrated    .....  543 
Plain  tiles  now  in  use  in  England;  Pan-tiles  and  various  other  forms  of 
tiles;  Modifications  of  pan -tiles,  illustrated    .         .        .        .        .        .  544 

Materials  for  glazing  and  coloring  roof-tiles 545 

Law  of  Edward  IV.  in  regard  to  digging  clay  for  tiles;  The  Tuileries 
and  derivation  of  the  name;  Modern  tile-covered  roofs,  with  illustra- 
tions; Forms  of  roofing-tiles,  with  illustrations;  Advantage  of  the 

tile  roof    ...         .         .         .         .  \ 546 

Roof  for  supporting  tile      .         .         ...''.         .         .         .         .  547 

Process  of  manufacturing  roofing-tiles;  Preparation  of  the  clay;  Knead- 
ing and  mixing  the  clay          .  "      .         .         .         .         .         .         .         .  548 

Moulding  table  or  bench  and  mould;   Manner  of  moulding;  Mode  of 
giving  the  set  or  curved  form  .  N  .         .         .         .         .         .  549 

Stacking  the  tiles;  Objections  to  roofing-tile  in  this  country;  Directions 
for  burning  roofing-tile  ....  .  .  .  .  .  .  •  55° 


XXxii  CONTENTS. 

PAGE 

Variety  of  articles  produced  in  large  tile  works,  the  clay  used  and 
mode  of  manufacture;  Preparation  of  clay  in  the  London  tileries; 
Kilns  used  for  burning  the  wares  produced 552 

Placing  pan-tiles  in  the  kiln;  Firing  the  kiln;  Influence  of  the  class  of 
goods  in  the  kiln  upon  the  quantity  of  fuel  consumed  in  a  burning; 
Colors  of  tiles  and  their  production  .  .  .  .  .  .  -553 

Patterns  of  roofing  tiles  employed  in  this  country;  Diamond  tiles; 
Shingle-tiles;  Pan-tiles 554 

Roofing-tiles  made  by  machinery  by  the  firm  of  J.  C.  Ewart  &  Co., 
Akron,  Ohio;  Burned  clay  as  roofing  material;  Definition  of  the  word 
tile;  Edward  L.  Morse  on  the  older  form  of  roofing-tiles  .  .  .555 

Countries  in  which  the  Normal  (Asiatic)  tiles  were  used;  The  most  artis- 
tic tiles  found  in  China,  Korea  and  Japan;  Cheapness  and  durability 
of  the  terra-cotta  roof-tile  .........  556 

A.  Rospide,  on  roofing-tile  in  France;  Requisites  of  every  good  roofing 
material;  Louis  H.  Gibson,  on  burnt  clay  for  covering  houses  .  .  557 

Demonstration  of  the  real  value  of  tile-roofs;  Story  of  the  establishment 
of  a  roofing-tile  factory  in  Indiana  .......  558 

Reasons  why  more  tile  have  not  been  used  in  the  United  States      .         •  559 

Number  of  tile-works  in  the  United  States;  Objections  to  the  old  form 
of  tile  . .  .  560 

Factories  working  under  the  patent  of  the  Clay  Shingle  Company; 
Value  of  roofing- tile  as  a  protection  against  fire;  Rates  of  insurance 
in  Germany;  Losses  by  fire  in  the  United  States  in  the  last  seven- 
teen years  .  .  ...  .  .....  .  .  561 

Value  of  the  clay  roof-covering  as  a  non-conductor;  Capital  required  in 
the  tile  business  .  . 562 

Trials  and  tribulations  of  a  man  who  tried  to  run  a  brick-yard;  Experi- 
ence and  knowledge  required  in  the  tile  business  .  .  .  .  563 

Tile-roof  the  coming  roof  in  the  United  States;  Comparison  of  the  price 
of  slate  and  of  tile;  Glazing  on  roofing-tiles,  etc.;  Porosity  of  new 
roofing-tile  .  . .  .  .  564 

Partial  object  of  glazing  roofing-tiles;  Use  of  glazed  roofing-tiles  of  dif- 
ferent colors  in  the  middle  ages;  Effect  of  covering  the  roof  of  the 
Ludwig  church,  at  Munich,  with  glazed  tiles;  Object  of  glazing; 
Usual  constitution  of  the  glaze  ........  565 

Importance  of  the  sand  in  the  glaze;  Sands  highly  valued  for  glazing 
purposes .  .  .'..-.  .  566 

Clays  yielding  by  themselves  good  glazes;  Abundance  of  suitable  sub- 
stances for  glazes;  Selection  of  materials  if  pure  colors  are  to  be  ob- 
tained  v  .  .567 

Materials  used  for  various  colors;  Application  of  the  glaze  to  the  tile; 
Principal  defects  shown  by  glazes  after  burning,  and  their  prevention; 
Importance  of  the  constitution  and  preparation  of  the  clay  .  .  .  568 

Different  mixtures  for  the  tile-mass;  Mixture  for  glazes;  Importance  of 
the  intimate  mixture  of  the  ingredients  of  the  tile-mass  .  .  .  569 


CONTENTS.  xxxiii 


Moulding  of  flat  tiles;  Coloring  of  the  glazing  mass;  Importance  of 
making  small  tests  with  all  colors 570 

Application  of  the  glaze;  Burning  in  the  glaze;  Experiments  in  Munich 
to  produce  a  red  glaze;  Form  and  size  of  roofing-tiles,  as  well  as  the 
mode  of  tiling  customary  in  Munich,  illustrated  ....  571 

Plain  glazing  of  roofing  tiles;  Dutch  directions  for  the  glaze;  Necessity 
of  an  accurate  knowledge  of  the  clay;  Preparation  of  the  glaze  .  572 

Application  of  the  glaze;  Reasons  for  the  necessity  of  grinding  the 
glaze  as  fine  as  possible;  Mishaps  in  burning  tiles  ....  573 

Means  of  preventing  the  tiles  from  baking  together  in  the  kiln;  The 
most  simple  glaze;  Glazing  with  salt;  Setting  glazed  tiles  in  the  kiln; 
Raw  glazing  of  Dutch  tiles;  Object  of  raw  glazing  .  .  ;*.  .  574 

Meissen  masses  for  Dutch  tiles;  Chamotte  mass;  White  covering  mass; 
Silver  gray  covering  mass;  Fawn  color  covering  mass;  Yellow  cover- 
ing mass;  Brown  covering  mass;  Green  covering  mass;  Blue  covering 
mass;  Mass  for  mending  before  glazing;  Cheap  glaze  especially  for 
the  colored  mass;  Finer  glaze  for  white  tiles  .  »  ..•;..  .  575 

Glazes  for  Dutch  tiles;  White  glaze;  Deep  red  glaze;  Dark  red  glaze; 
Azure  blue  glaze;  Preparation  of  a  good  glazing  mixture  *  «  ;.  .  576 

Glazes  for  roofing  tiles;  Object  of  glazing  roofing  tiles;  Scaling  of 
slightly  burned  tiles;  Tiles  to  be  glazed  must  be  burned  hard;  Ex- 
periment in  saturating  a  tile  with  water  and  allowing  it  to  freeze; 
Necessity  of  arranging  the  fusing  point  of  the  glaze  in  accordance 
with  the  slagging  point  of  the  clay;  Decomposition  of  glazes  by 
atmospheric  influences  ...,%......  577 

Adaptation  of  Prof.  Weber's  method  of  testing  glasses  as  to  their  power 
of  resistance  agaibst  the  atmosphere,  to  testing  glazes;  The  nature 
of  the  glazes  to  be  used  dependent  upon  the  temperature  they  are  to 
sustain;  Composition  of  the  most  readily  fusible  and  the  most  re- 
fractory lead  glazes  .  i»  . 578 

Glazing  tiles  in  which  a  dark  color  is  the  chief  requisite;  Average  com- 
position of  white  enamels;  Temperatures  at  which  the  glazes  may  be 
employed  ,  ...  .  .  .  .  .  .  .  .  579 

Most  important  glazes  for  roofing  tiles  and  the  form  in  which  they  are 
employed  ,  .  .  .  .  .  .  .  .  .  .  .  580 

On  what  the  higher  and  lower  fusing  points  of  glazes  chiefly  depend; 
Fusing  point  for  glazes  free  from  lead;  The  Merrill  roofing  tile  ma- 
chine, with  detailed  description  and  illustrations  ....  581 

Machine  for  moulding  roofing  tile  from  plastic  clay,  with  detailed  de- 
scription and  illustrations  .,',,.  ~~.  •.,  .  .  .  •  .  585 

Tile  barrows,  described  and  illustrated 589 


XXxiv  CONTENTS. 


CHAPTER    XVII. 

THE  MANUFACTURE  OF  MOSAICS  AND  IMITATION  INLAID  AND 
INTARSIA  SURFACES. 

PAGE 

Origin  of  the  method  of  cementing  various  kinds  of  stones,  glass,  etc. ; 
Chief  use  of  mosaic  work  of  glass  and  some  of  the  finest  specimens; 
Use  of  mosaic  work  in  marble;  Mosaic  manufacture  at  the  present 
day  in  Rome  ............  590 

Time  required  to  finish  a  mosaic  copy  of  a  painting;  Manner  of  making 
the  mosaic;  Shades  of  "smalts"  in  use;  Polishing  the  mosaic; 
Mosaic -work  of  Florence 591 

Invention  of  Mr.  Robert  Eltzner,  of  New  York  City,  for  the  manufact- 
ure of  mosaic  plates  for  pavements,  wall  ornamentation,  furniture, 
etc.,  with  detailed  description  and  illustrations  .....  592 

Advantages  of  this  method        .........  595 

Imitation  inlaid  and  intarsia  surfaces;  Invention  for  the  production  of 
tiles,  table  tops,  wainscoting,  panels,  work-boxes,  articles  of  furni- 
ture, etc.,  with  detailed  description  and  illustrations  .  596 

Index  . .         .599 


UNIVERSITY 


MANUFACTURE  OF  BRICK,  TILES, 
AND  TERRA-COTTA. 


CHAPTER   I. 

THE   HISTORY   OF   BRICK. 

THERE  is  little  doubt  that  clay,  in  combination  with  such 
materials  as  would  bind  it  together  in  a  compact  mass,  was 
employed  in  the  structure  of  the  primitive  human  dwelling. 
In  course  of  time  this  method  of  construction  was  superseded 
by  the  use  of  the  same  plastic  substance,  moulded  either  with 
or  without  other  ingredients  into  suitable  forms,  which  were 
afterward  dried  or  burned — the  result  being  the  production  of 
the  article  known  as  "brick." 

In  the  words  of  Bishop  Berkeley :  "  Westward  the  course  of 
empire  takes  its  way,"  and  in  order  to  trace  the  history  of  Art 
we  must  backward  follow  its  course  to  the  far  East,  to  the 
dreary  delta  of  the  Nile,  and  there,  among  the  mounds  of  the 
arid  wastes  which  cover  the  palaces  of  kings,  the  monuments 
of  an  extinct  faith  and  the  graves  of  dead  nations,  trace  so  far 
as  we  can  its  early  history  and  development. 

In  Egypt  the  art  of  pottery  is  credited  to  the  inventive  genius 
of  the  gods.  It  is  to  Num,  the  oldest  of  created  beings,  that 
the  earliest  practice  of  the  potter's  art  is  attributed,  and  it  is 
this  god  who  is  credited  with  having  moulded  the  human  race 
on  his  potter's  wheel ;  the  heavens  and  the  earth,  the  air,  the 
mountains,  hills  and  streams,  had  previously  been  made  by 
Num,  who  then  suspended  the  sun  and  moon  between  the  earth 
and  the  heavens,  and  after  having  made  man,  whom  he  formed 
out  of  the  black  Nilotic  clay,  he  then  breathed  into  his  nostrils 

(i) 


2  BRICK,  TILES   AND   TERRA-COTTA. 

the  breath  of  life.  This  attribution  of  the  invention  of  the  art 
of  pottery  to  the  gods  is  unequivocal  corroborative  proof  of 
the  statement  that  this  art  was  employed  prior  to  the  historical 
period. 

Brick  have  been  employed  from  the  earliest  times  in  the 
execution  of  many  undertakings  of  grandeur  and  magnitude. 
A  complete  history  of  brickmaking  would  be  analogous  to  that 
of  civilization  with  its  advances  and  declines,  for  the  authentic 
record  of  this  branch  of  pottery  is  older  than  that  of  any  other 
ceramic  production,  extending  through  forty-one  centuries ; 
the  descendants  of  the  sons  of  Noah,  who  journeyed  from  the 
East  and  located  on  the  plains  of  Shinar,  being  the  first  potters 
of  whom  we  have  positive  attestation. 

In  our  own  times  structures  of  great  altitude  have  been  pro- 
ected ;  but  the  Washington  Monument  and  similar  undertak- 
ings appear  insignificant  when  compared  to  the  stupendous 
conceptions  of  those  bold  men,  who,  in  2247  B.  C.,  said:  "  Go 
to,  let  us  make  brick,  and  burn  them  thoroughly."  And  they 
said :  "  Go  to,  let  us  build  us  a  city  and  a  tower,  whose  top 
may  reach  unto  heaven."  * 

The  story  of  the  manner  in  which  this  proposed  monopoly  of 
that  portion  of  space  between  earth  and  heaven  was  defeated 
by  confusion  of  the  tongues  of  the  builders,  is  too  familiar  for 
repetition  here.  But  that  something  was  accomplished  will 
appear  from  the  speech  of  Moses  to  the  Israelites,  delivered 
seven  hundred  and  ninety-six  years  later,  in  which  cities  in  the 
land  of  Canaan  are  referred  to  as  being  great  and  walled  up  to 
heaven. f 

In  tracing  development  in  the  art  of  brick-making  we  find 
that  progress  has  often  been  slow  and  uncertain ;  it  has  flour- 
ished in  ages  of  prosperity  with  other  arts,  and  like  them  it  has 
been  lost  in  ages  of  darkness ;  but  as  with  them  it  awoke  with 
the  Renaissance,  and  is  steadily  improving  with  the  progress 
of  time  and  the  spread  of  knowledge. 

Machinery  is  doing  much  to  lighten  labor,  but  in  all  ages  the 

*  Genesis  xi.  3,  4.  f  Deut.  i.  28. 


THE   HISTORY    OF   BRICK.  3 

work  required  to  make  brick  has  been  of  the  hardest  kind,  and 
many  have  been  faint  with  toil  in  their  production,  in  modern 
as  well  as  in  ancient  times. 

My  observation  leads  me  to  say  that  the  old  manual  method 
of  brick-making  has  destroyed  many  a  man  in  the  prime  of  life, 
and  has  undermined  the  constitutions  and  wrecked  the  systems 
of  the  most  robust  natures. 

The  children  of  Israel,  as  early  as  1706  B.  C.,  were  made  to 
serve  the  Egyptians  with  rigor,  and  their  lives  were  made  bitter 
with  hard  bondage  in  mortar  and  in  brick ;  and  Pharaoh,  in 
1491  B.  C.,  in  order  to  increase  the  burdens  and  labor  of  the 
Israelites,  commanded  the  task-masters,  saying,  "Ye  shall  no 
more  give  the  people  straw  to  make  brick,  as  heretofore ;  let 
them  go  and  gather  straw  for  themselves,  and  the  tale  of  the 
bricks,  which  they  did  make  heretofore,  ye  shall  lay  upon 
them."* 

Pictures  illustrating  the  above  passages  are  still  preserved  on 
tombs  in  Thebes,  in  which  some  of  the  laborers  are  represented 
carrying  water  in  large  pots  to  temper  the  clay ;  others  carry 
on  their  shoulders  large  masses  oi  clay  to  the  moulder,  while 
others  still  are  bearing  off  the  brick,  and  laying  them  out  on 
the  ground  to  dry,  the  dried  brick  being  carried  in  yokes  sus- 
pended from  the  shoulders  of  bowed  and  weary  laborers. 
Task-masters,  who  were  personally  responsible  for  the  labor  of 
their  gangs,  are  plentifully  represented,  observing  that  there 
was  no  shirking  of  the  labor  or  slighting  of  the  work. 

Rameses  II.  of  the  Egyptians,  who  is  the  same  as  the  great 
Sesostris  of  the  Greeks  and  the  Pharaoh  of  the  Old  Testament, 
reappears  as  a  mummy  before  the  world  to-day.  The  pride 
which  carried  him  in  conquest  over  half  the  eastern  world,  the 
dignity  that  enabled  him  for  many  years  to  support  the  weight 
of  empire,  the  hardness  of  heart  that  made  him  so  severe  a 
task-master  to  the  Hebrews,  and  the  unyielding  obstinacy  that 
made  him  do  prolonged  battle  with  the  chosen  servants  of  God, 
are  all  visibly  stamped  upon  his  countenance  now,  as  when 

*  Exodus,  v.  7,  8. 


4  BRICK,  TILES    AND   TERRA-COTTA. 

Moses  stood  before  him  vainly  pleading  that  he  would  "  let  the 
people  go."  How  much  better  it  would  be  for  those  who  op- 
press the  people  to  lift  their  heavy  hands  while  still  alive  than 
to  stand  either  in  cerecloth  or  in  history,  as  Rameses  does,  an 
immortal  monument  of  injustice,  tyranny,  and  wrong. 

The  mud  of  the  Nile  is  the  only  material  in  Egypt  suitable 
for  brick-making ;  the  modern  plan  is  the  same  as  the  old ;  a 
bed  is  made  into  which  are  thrown  large  quantities  of  cut  straw, 
mud  and  water,  and  this  is  tramped  into  pug,  removed  in 
lumps,  and  shaped  in  moulds,  or  by  the  hands.  The  moulded 
clay  is  sun-dried,  not  burned,  the  brick  of  Egypt,  both  ancient 
and  modern,  being  adobes. 

Herodotus  testifies  that  the  walls  of  Babylon  were  built  of 
brick  made  from  the  clay  thrown  from  the  trenches  surrounding 
the  place.  Accounts  of  the  extraordinary  mounds  of  brick  at 
Birs  Nimrod,  the  supposed  site  of  Babylon,  and  the  remains  of 
other  ancient  cities  of  the  stoneless  plains  of  the  Euphrates  and 
Tigris,  have  been  given  by  noted  Eastern  travelers.  The  buried 
palaces  of  Nebuchadnezzar  have,  for  a  long  series  of  years, 
provided  brick  for  all  the  buildings  in  the  neighborhood;  there 
being  scarcely  a  house  in  Hillar,  a  city  of  over  8,000  inhabitants, 
built  close  to  the  ruins  of  ancient  Babylon,  which  is  not  almost 
entirely  built  with  them.  "To  this  day,"  says  Layard,  "  there 
are  men  who  have  no  other  trade  than  that  of  gathering  brick 
from  this  vast  heap,  and  taking  them  for  sale  to  neighboring 
towns  and  villages,  and  even  to  Bagdad."  Many  brick  found 
in  this  ruin  are  coated  with  a  thick  enamel  or  glaze.  The 
colors  have  resisted  the  effects  of  time,  and  present  their  orig- 
inal brightness. 

On  every  brick  that  was  made  during  the  reign  of  Nebuchad- 
nezzar it  was  his  custom  to  have  his  name  stamped,  and  Sir 
Henry  Rawlinson,  the  Oriental  scholar,  in  examining  the  brick 
in  the  walls  of  the  modern  city  of  Bagdad,  on  the  borders  of 
the  Tigris,  discovered  on  each  brick  the  clear  traces  of  that 
royal  signature. 

The    Babylonish    brick  were  usually  of    three   colors :    red, 


THE    HISTORY   OF   BRICK.  5 

pale-yellow,  and  blue,  and  also  in  all  ancient  Egyptian  decora- 
tions the  primary  colors,  red,  yellow,  and  blue,  were  principally 
employed  ;  green  was  the  only  secondary,  to  which  were  added 
black  and  white.  The  profuse  employment  of  colored  decora- 
tion is  the  distinctive  feature  of  Babylonish  architecture,  the 
brick  being  stamped  out  of  a  mould,  and  impressed  with  cunei- 
form inscriptions,  which  is  a  certain  form  of  writing,  the  com- 
ponent parts  of  which  may  be  said  to  resemble  either  a  wedge, 
the  barb  of  an  arrow,  or  a  nail,  the  inscription  being  placed  in  a 
sunken  rectangular  panel.  The  sizes  of  the  Babylonish  brick 
vary,  the  burned  ones  being  thirteen  inches  square  and  three 
inches  thick ;  the  adobes  or  sun-dried  brick  measuring  from  six 
to  sixteen  inches  square,  and  from  two  to  seven  inches  thick. 
The  adobes  were  laid  in  clay,  the  work  being  striped  hori- 
zontally, every  four  or  five  feet  in  height,  with  thick  layers  of 
reed  matting  steeped  in  bitumen  to  form  the  bond ;  the  burned 
brick  were  laid  while  warm  in  hot  bitumen,  the  bond  being 
formed  in  the  laying.  In  addition  to  the  above  kinds  there 
were  triangular  brick  for  corners  of  walls,  and  wedge-shaped 
brick  for  arches,  which  were  sometimes  concave  below  and 
convex  on  top. 

Recent  excavations  have  been  made  on  the  site  of  the 
Pithom,  the  treasure  city  built  by  King  Rameses  II.  with  the 
bondage-labor  of  the  children  of  Israel.  The  buildings  prove 
to  have  consisted  almost  entirely  of  tremendous  store-houses 
built  of  adobes.  Some  of  these  sun-dried  brick  were  made 
with  straw  and  some  without  it. 

The  pyramids  of  Aboo  Roash,  Dashour,  Howara,  and  Illa- 
hoon,  were  constructed  of  adobes ;  unburnt  brick  have  also 
been  found  in  the  joints  near  the  foundation  of  the  third  pyra- 
mid of  Gizeh.  The  bricks  in  the  pyramid  at  Aboo  Roash 
contain  no  straw,  and  those  in  the  pyramid  at  Saqqara  contain 
only  a  small  quantity  of  straw  on  the  outside.  The  northern 
pyramid  at  Dashour  was  built  of  brick  about  sixteen  inches 
long,  three  inches  wide,  and  four  and  three-quarters  inches 
thick.  The  southern  pyramid  at  Dashour  is  constructed  of 


6  BRICK,  TILES   AND   TERRA-COTTA. 

brick  fifteen  and  one-quarter  inches  long  by  seven  and  three- 
quarter  inches  in  width  and  five  and  one-half  inches  in  thick- 
ness, or  thirteen  and  one-half  inches  long,  six  and  one-half 
inches  wide,  and  four  and  one-half  inches  in  thickness,  and 
these  brick  contain  a  large  quantity  of  straw.  The  brick  used 
in  the  construction  of  the  pyramid  of  Howara  measure  seven- 
teen and  one-half  inches  in  length,  eight  and  three-eighths 
inches  in  width,  five  and  one-eighth  inches  in  thickness,  and 
like  the  brick  used  in  the  southern  pyramid  at  Dashour,  they 
contain  a  large  quantity  of  straw. 

The  Fayoom  and  the  Delta,  which  contain  vast  quantities  of 
rich  alluvial  mud,  and  which  are  remote  from  the  principal 
quarries,  undoubtedly  presented,  at  the  most  ancient  period  of 
Egyptian  history,  the  appearance  of  an  enormous  brick  field. 
The  mud  brought  down  by  the  Nile  was  particularly  suitable 
for  the  manufacture  of  brick  and  pottery. 

Like  the  valley  of  the  Nile,  the  plains  of  Assyria  were  abun- 
dantly supplied  with  clay  by  inundations  of  the  Tigris  and 
Euphrates,  and  the  material  was  largely  employed  for  the 
manufacture  of  brick,  which  were  easily  moulded  from  the 
common  clay  tempered  with  water  and  mixed  with  stubble  in 
small  quantities  to  bind  the  mass  together.  The  formation  of 
the  high  artificial  platforms  or  mounds  on  which  the  Assyrian 
city  edifices  were  erected  was  the  chief  employment  for  brick. 
These  platforms  were  usually  about  twenty  feet  high,  and  the 
clay  for  the  manufacture  of  the  brick  was  excavated  from  the 
trench  or  dry  ditch  by  which  the  city  was  surrounded.  But 
in  addition  to  this  employment  they  were  also  used  in  enor- 
mous quantities  for  the  walls  of  the  city,  and  also  for  the  con- 
struction of  the  edifices  of  the  citizens  and  the  burial-places  of 
the  dead.  The  brick  were  probably  made  in  a  square  wooden 
mould  of  the  proper  depth,  and  some  of  them  are  impressed 
with  marks  somewhat  resembling  the  Egyptian.  The  Assyrian 
adobe  brick  are  not  so  carefully  and  regularly  made  as  those  of 
Egypt  and  Babylon,  and  there  is  great  difficulty  in  accurately 
measuring  them.  The  Assyrians  employed  burned  brick  prin- 


THE    HISTORY   OF   BRICK.  7 

cipally  in  positions  where  it  was  desirable  to  keep  out  moisture, 
and  in  addition  to  being  used  for  ground-floors  and  outer-walls 
of  the  palaces,  they  were  also  employed  for  the  construction  of 
some  tombs. 

The  unburned  brick  are  called,  in  hieroglyphs,  teba,  which 
is  the  same  word  as  the  one  used  for  a  chest  or  box,  and  the 
term  probably  originated  from  the  shallow  wooden  box  or 
mould  in  which  they  were  shaped  and  afterwards  turned  out. 
It  is  thought  that  the  business  of  brickmaking  was  a  royal 
monopoly  in  Egypt,  as  a  very  large  number  of  brick  are  found 
in  that  country  with  praenomens  and  names  of  monarchs, 
Thothmes  I.  and  III.,  Amenophis  II.,  Thothmes  II.,  and 
Amenophis  III.,  of  the  Eighteenth  dynasty ;  of  Rameses  II., 
of  the  Nineteenth,  of  the  High  Priests  of  Amen  Ra,  named 
Pthameri,  Parennefer,  and  Ruma,  etc. 

No  brick  appears  to  have  been  impressed  before  the  Eigh- 
teenth dynasty,  nor  later  than  the  Twenty-first.  Thothmes  III. 
is  believed  to  be  the  prince  who  reigned  at  the  time  of  the 
Exodus  of  the  Hebrews.  The  brick  made  during  the  reign  of 
this  prince  are  impressed  with  his  Cartouche,  which  is  an  oval, 
on  which  the  hieroglyphic  characters  used  for  his  name  are 
stamped,  and  adobes  made  in  his  time  were  12  inches  long,  9 
inches  wide,  and  6^  inches  thick,  and  one  in  the  British 
Museum  weighs  37  pounds  and  10  ounces. 

It  is  probable  that  the  brick  bearing  the  names  of  kings 
were  intended  to  be  used  in  the  construction  of  public  works. 

It  is  not  probable  that,  in  either  Assyria  or  Chaldea,  any  re- 
strictions were  imposed  as  to  the  length  of  time  which  the  brick 
should  be  dried  before  being  used,  and  this  statement  is  cor- 
roborated by  the  evidence  of  M.  Place,  who  excavated  numer- 
ous shafts  through  the  massive  Assyrian  buildings  for  the  pur- 
pose of  exploration,  and  from  these  shafts  it  was  possible  to 
form  an  idea  of  the  condition  in  which  the  brick  had  been  laid 
in  the  walls.  The  sides  of  these  exploring  shafts  showed  a 
uniform  surface  without  any  evidence  of  joints.  It  has  been 
supposed  by  some  that  the  crude  brick  were  first  dried  in  the 


8  BRICK,  TILES   AND   TERRA-COTTA. 

sun,  and  then  before  being  used  were  dampened  with  water 
before  being  laid ;  but  this  supposition  is  repudiated  by  Place, 
who  explains  that,  should  the  brick  have  been  laid  in  that 
manner,  each  joint  would  be  marked  and  made  more  dis- 
tinguishable by  rather  darker  tints  than  the  remaining  portions 
of  the  wall,  but  there  is  in  reality  no  such  discoloration.  The 
fact  that  the  horizontal  portions  are  often  distinguishable  from 
each  other  by  their  differences  of  tint  proves  that  the  excava- 
tions of  Place  were  made  through  brick,  and  not  through  a  mass 
of  earth  solidly  compressed  by  employing  the  rammer. 

It  is  not  possible  that  sun-dried  brick  ever  become  sufficiently 
hard  not  to  be  destroyed  by  the  action  of  water.  The  walls  of 
Matinea  were  thrown  down  by  Agesipolis,  King  of  Sparta,  who 
turned  the  water  of  the  Ophia  along  the  base  of  the  walls  of 
unburnt  brick.  The  walls  of  Eion,  on  the  Strymon,  were 
attacked  in  the  same  manner  by  Cimon,  son  of  Miltiades. 

Unburnt  brick  were  never  regarded  by  the  inhabitants  of 
Mesopotamia  as  a  safe  building  material,  and  experience 
demonstrated  the  necessity  of  supplementing  with  huge  but- 
tresses the  buildings  in  which  the  material  was  employed,  and  it 
is  probable  from  the  evidence  of  those  who  have  explored  these 
ruins  that  the  supplemental  supports  were  more  thoroughly  and 
carefully  constructed  than  the  buildings,  the  walls  of  which  they 
were  intended  to  sustain.  The  crude  brick  walls  of  Chaldean 
buildings  were  perforated  with  numerous  ventilating  tunnels, 
through  which  the  warm  air  could  penetrate,  and  thus  dissipate 
any  moisture  that  might  be  contained  in  the  brick.  Perfora- 
tions of  this  kind  have  been  discovered  in  the  ruins  of  Babylon 
and  also  in  other  Chaldean  cities ;  but  in  Assyria  no  such  open- 
ings of  the  kind  which  we  have  described  for  the  admission  of 
air  have  been  found.  It  is  the  almost  unanimous  opinion  of 
explorers  that  sun-dried  brick  were  never  left  unprotected  in 
Mesopotamia,  the  material  being  commonly  protected  by  a  thin 
coat  of  stucco.  It  is  stated  by  M.  Place,  that  at  Nineveh  this 
stucco  was  formed  by  a  mixture  of  burned  chalk  and  plaster, 
the  compound  producing  a  sort  of  white  gum,  which  adhered 


THE   HISTORY    OF   BRICK.  9 

intimately  to  the  clay  wall.  It  is  probable  that  many  buildings 
had  no  outward  ornament  beyond  that  imparted  by  the  brilliant 
whiteness  of  this  stucco,  the  effect  of  which  is  still  to  be  seen 
even  at  the  present  time  in  the  whitewashed  houses  of  the  East. 

The  great  perfection  to  which  the  ancients  carried  the  art  of 
brick-making  is  probably  due  to  the  abundance  of  labor,  plenty 
of  time  to  devote  to  each  stage  of  the  work,  their  great  patience 
and  painstaking,  and  the  natural  drying  and  preserving  climate 
of  the  East.  The  dry,  warm  atmospheres  of  Egypt,  Assyria  and 
Babylonia,  which  countries  were  the  nurseries  of  the  ceramic 
arts,  have  kept  in  a  good  state  of  preservation  for  more  than 
three  thousand  years  the  sun-dried  brick  so  common  in  those 
countries ;  many  well-preservad  adobes  are  also  found  in  towns 
and  walls  of  ancient  India. 

Brick,  burned  and  unburned,  were  employed  in  the  con- 
struction of  the  Great  Wall  of  China,  which  is  the  most  remark- 
able fortification  ever  erected  by  human  hands  ;  millions  of  men 
were  employed  for  the  space  of  ten  years  in  its  construction, 
and  it  was  completed  in  21 1  B.  C.  The  length  was  about  1250 
miles,  the  height  averaging  about  2,2  feet ;  each  face  of  the  wall 
was  built  of  hewn  stone  or  brick,  and  filled  in  between  with 
earth ;  it  was  wider  at  the  bottom  than  at  the  top,  which  was 
sufficiently  wide  for  six  horsemen  to  ride  abreast ;  it  was  built  by 
the  great  Emperor  of  China,  Shee-Hoang-Ti,  who  is  the  national 
hero. 

In  Spain  the  use  of  sun-dried  brick  has  more  or  less  con- 
tinued in  some  portions  even  to  the  present  day.  In  Mexico, 
sun-dried  brick  have  been  continuously  employed  for  many 
centuries,  and  the  early  Spanish-American  buildings  in  Cali- 
fornia were  commonly  constructed  of  adobes.  The  exterior 
walls  of  the  buildings  in  Mexico  and  the  Spanish-American 
buildings  in  California  were  often  covered  with  a  bluish  stucco 
or  enamel,  which  was  sometimes  applied  after  the  erection  of  a 
building  or  sometimes  before.  In  the  southern  portion  of 
Texas,  adobes  are  still  often  used  for  the  construction  of  dwell- 
ings. In  the  southern  portion  of  the  State  of  Kansas,  which  is 


10  BRICK,  TILES   AND   TERRA-COTTA. 

often  visited  with  wind  storms  which  destroy  frame  structures, 
adobes  are  often  employed  for  buildings ;  the  walls  are  com- 
monly carried  up  to  the  height  of  one  story,  and  the  roof  has 
a  steep  pitch  and  extends  about  two  feet  six  inches  beyond  the 
faces  of  the  walls.  The  steep  roofs  give  a  half  story  or  attic  in 
the  upper  portion  of  the  dwelling,  and  the  wide  projecting  eaves 
protect  the  walls.  The  adobes  are  made  about  eighteen  inches 
square  and  four  inches  thick,  and  half  brick  to  correspond. 
These  sun-dried  brick,  as  were  those  of  old,  are  sometimes 
made  with  straw  and  sometimes  without.  Buildings  constructed 
of  adobes  are  termed,  in  the  Western  States,  "  dobies,"  and  in 
Mexico,  Texas,  Colorado,  New  Mexico,  and  Arizona,  buildings 
so  constructed  are  called  "adobe  houses." 

It  is  probable  that  burned  clay  did  not  find  great  favor  with 
the  ancient  Greeks,  as  they  possessed  an  abundance  of  stone. 

The  walls  of  Athens,  on  the  side  towards  Mount  Hymettus, 
were  built  of  brick,  and  this  is  probably  the  largest  undertak- 
ing in  which  they  were  employed  by  the  Greeks. 

The  use  of  brick  for  architectural  construction  was  never,  at 
any  period,  extensive  in  Greece,  but  in  some  few  cases  they 
were  employed  in  minor  public  edifices.  Their  first  applica- 
tion has  been  attributed  to  Hyperbius,  of  Crete,  and  Euryalus 
or  Ayrolas.  The  brick  were  made  with  a  mould,  and  were 
named  after  the  number  of  palms'  lengths. 

In  the  first  century  of  the  Christian  era,  while  the  brick  made 
by  the  Romans  were  of  a  superior  quality,  those  made  by  the 
Greeks  were  very  inferior. 

But  little  is  known  of  the  material  used  in  the  early  buildings 
of  the  Latin  cities ;  yet,  judging  from  the  great  extent  and 
destructiveness  of  the  fires  in  Rome,  it  is  inferred  that  wood 
entered  largely  into  the  construction  of  buildings  up  to  the 
time  of  Nero.  During  his  reign,  in  A.  D.  64,  two-thirds  of  the 
city  was  destroyed  by  fire.  Augustus,  who  devoted  so  much 
time  and  thought  to  beautifying  Rome,  had  restricted  the 
height  of  buildings  to  seventy  feet,  but  this  height  was  still 
further  curtailed  by  Nero  after  the  conflagration,  and  in  the  re- 


THE   HISTORY    OF   BRICK.  I  I 

building  a  certain  portion  of  the  houses  were  constructed  of  a 
fire-proof  stone  from  Gabii  and  Alba. 

With  the  conquest  of  Carthage,  Greece,  and  Egypt,  the 
Romans  became  acquainted  with  the  arts  of  those  subjugated 
countries,  and  tried  to  improve  upon  and  use  them  for  the  em- 
bellishment of  the  imperial  city,  and  it  was  most  likely  their 
innate  desire  for  improvement  that  led  to  the  burning  of  brick 
in  kilns. 

Although  burnt  brick  were  used  in  the  tower  of  Babel,  and 
to  face  the  adobes  used  in  the  building  of  the  walls  and  palaces 
of  Babylon,  it  is  probable  that  the  credit  of  first  burning  brick 
in  kilns  belongs  to  the  Romans ;  but  it  is  hard  to  fix  the  time 
when  this  improvement  took  place. 

Layers  of  thin  brick,  separating  the  tufa  surface  into  panels, 
called  opus  reticulatum,  were  used  in  the  time  of  Augustus.  In 
the  time  of  Nero  the  walls  were  faced  entirely  with  excellent 
brick-work,  called  opus  lateritium. 

Pliny  says  that  the  brick  made  in  Greece  at  this  time  were 
very  inferior,  and  not  fit  to  be  used  in  the  construction  of  a 
Roman  dwelling,  and  that  no  party-wall  was  allowed  to  be  more 
than  eighteen  inches  in  thickness,  and  that  the  material  would 
not  support  one  story. 

The  brick  must  have  been  of  a  very  poor  quality,  or  else 
Pliny  greatly  misjudged  their  strength,  for  at  the  present  time 
many  buildings  are  being  constructed  four  or  five  stories  high, 
with  the  party-walls  for  most  of  the  way  only  nine  inches  in 
thickness,  of  the  poorest  kind  of  "  salmon"  brick,  from  which 
the  water  has  barely  been  driven  out  by  the  action  of  the  heat ; 
and  if  Pliny  could  see  some  of  the  brick  now  used  he  would 
quake  for  the  safety  of  the  occupants  of  some  modern  hotels, 
apartment-houses,  office-buildings,  and  dwellings  that  have  re- 
cently been  erected  for  speculative  purposes  in  London  and 
some  portions  of  this  country. 

In  the  first  century  of  the  Christian  era  the  brick  were  better 
than  at  other  periods ;  they  were  large,  flat,  and  thin,  generally 
two  feet  square  and  one  inch  thick,  and  were  what  we  call 


12  BRICK,  TILES   AND   TERRA-COTTA. 

Roman  tiles,  but  were  used  for  building  walls,  and  not  merely 
for  roofing  or  pavements ;  the  facing  brick  were  triangular,  the 
broad  side  being  outwards.  But  brick  gradually  became  thicker 
and  shorter,  until  in  the  fourth  century  they  were  very  often  as 
many  as  four  to  a  foot  on  the  face  of  the  wall,  which  is  about 
the  same  as  in  modern  structures. 

The  Romans  did  not  build  their  walls  entirely  of  brick ;  they 
were  used  only  as  a  facing  or  veneering,  the  same  as  we  use 
front  or  pressed  brick,  the  remainder  or  backing  of  a  wall  being 
of  concrete,  and  thus  we  find  that  a  large  number  of  the  great 
Roman  buildings  are  constructed  of  concrete,  faced  with  brick. 

The  brick-work  of  the  first  two  centuries  of  the  Christian  era, 
the  crowning  period  of  art  in  Rome,  was  superior  to  any  other. 
In  the  third  century  there  was  barely  a  perceptible  change,  but 
in  the  fourth  there  was  a  most  decided  deterioration,  and  brick- 
work went  back  with  the  times,  old  material  being  re-used  ex- 
tensively, as  in  the  arch  of  Constantine. 

Knowledge  of  the  art  of  brick-making  has  probably  at  no 
time  become  entirely  extinct  in  the  East,  but  after  the  fourth 
century,  in  sympathy  with  the  decline  of  all  other  arts,  and  the 
dying  Roman  civilization,  the  knowledge  of  this  art  gradually 
expired,  and  was  lost  to  Western  Europe. 

The  Romans  made  brick  extensively  in  Germany  and  Eng- 
land, and  though  it  might  seem  strange  that  such  an  art,  when 
once  acquired,  should  have  been  lost,  nevertheless  the  remains 
of  buildings  between  the  Roman  times  and  the  thirteenth  cen- 
tury show  no  evidence  of  brick  having  teen  made  in  England. 
In  a  few  instances  only  were  they  re-used  as  old  material  from 
buildings  left  by  the  Romans,  as  at  Colchester  and  St.  Alban's 
Abbey — the  old  Roman  town  of  Verulamium,  near  which  the 
latter  is  situated,  supplying  material  for  it. 

The  buildings  of  the  Anglo-Saxons  were  usually  of  wood, 
rarely  of  stone  until  the  eleventh  century,  and  it  is  not  improb- 
able that  the  primitive  English  churches  may  be  among  the 
earliest  stone  buildings  of  Western  Europe,  after  the  time  of  the 
Romans.  In  these  buildings  the  arches  are  generally  plain, 


THE    HISTORY    OF   BRICK.  13 

but  sometimes  they  are  worked  with  rude  but  massive  mould- 
ings. Some  arches  are  constructed  of  brick,  all  of  them  taken 
from  some  Roman  building,  as  at  Bixworth,  or  sometimes  stones 
are  employed,  and  these  usually  have  a  course  of  brick  or  thin 
stones  laid  upon  the  top  of  the  arch,  as  at  Britford  church, 
Wiltshire. 

It  has  been  thought  that  brick  were  made  in  England,  under 
the  direction  of  Alfred  the  Great,  as  early  as  A.  D.  886,  and  it 
is  possible  that,  in  rebuilding  London  and  other  cities  which 
had  been  destroyed  by  the  Danes,  brick  were  used ;  but  this  is 
not  probable,  as  there  are  but  few  buildings  in  any  part  of  West- 
ern Europe  now  in  existence  that  are  earlier  than  the  eleventh 
century,  and  if  brick  were  made  in  the  time  of  Alfred,  in  Eng- 
land, there  are  none  at  present  in  existence,  and  no  authentic 
history  of  any  building  erected  in  his  reign  in  which  they  are 
said  to  have  been  used,  and  it  is  most  probable  that  the  earliest 
true  modern  or  Flemish  brick  building  existing  in  England  is 
Little  Wenham  Hall,  in  Suffolk,  which  was  erected  in  A.  D. 
1260. 

In  the  reign  of  Henry  VI.  brick  construction  was  not  general, 
Hurstmonceaux  Castle,  Sussex,  built  early  in  his  reign,  being 
one  of  the  principal  brick  buildings  of  that  period ;  but  under 
Henry  VIII.  and  Elizabeth  the  manufacture  of  brick  flourished, 
and  they  were  used  mostly  for  large  buildings,  the  smaller  ones 
being  of  timber  construction,  in  which  small  panels  of  orna- 
mental brickwork  were  sometimes  formed  and  exposed  between 
the  upright  studs. 

Only  a  few  instances  of  early  fourteenth  century  brick-work 
occur,  and  they  are  towards  the  close  of  the  style ;  but  in  the 
fifteenth  century  brickwork  became  common,  and  we  have  in 
the  Lollards'  Tower,  of  Lambeth  Palace,  built  in  A.  D.  1454, 
and  the  Manor  House,  or  older  portion  of  Hampton  Court 
Palace,  Middlesex,  built  in  A.  D.  1514,  good  examples  of  the 
English  brick  architecture  in  mediaeval  times.  The  ecclesias- 
tical and  palatial  architecture  of  Italy  of  this  period  is  rich  in 
many  beautiful  specimens  of  brick-work,  and  in  addition  to  the 


14  BRICK,  TILES   AND   TERRA-COTTA. 

employment  of  colored  decorative  brick- work,  the  most  elabor- 
ate mouldings  and  ornamentation  in  terra-cotta  and  brick  are 
exhibited. 

Until  the  first  quarter  of  the  seventeenth  century,  the  brick 
made  in  England  were  of  many  different  sizes,  but  by  Charles 
I.,  in  A.  D.  1625,  their  size  was  regulated  and  made  nearly 
uniform. 

After  the  great  fire  of  London  in  September,  A.  D.  1666, 
brick  was  the  material  universally  used  in  the  reconstruction, 
and  ornaments  carved  with  the  chisel  were  introduced  into 
some  of  the  brick-work  erected  towards  the  last  of  that  century 
in  that  city. 

In  A.  D.  1784,  brick  were  subjected  to  taxation  by  George 
III.,  which  burden  was  not  repealed  until  A.  D.  1850;  the  tax 
for  this  time,  two-thirds  of  a  century,  averaging  about  43.  jd. 
per  thousand  for  common  brick,  and  about  los.  per  thousand 
for  the  finer  grades. 

The  material  of  which  a  town  is  built  depends  generally  upon 
the  geology  of  the  surrounding  district ;  as  in  a  mountainous 
country,  like  Scotland,  cities  of  stone,  such  as  Edinburgh,  Glas- 
gow, and  Aberdeen,  naturally  abound ;  but  London  and  most 
of  the  great  cities  of  England,  being  situated  in  alluvial  valleys 
and  plains,  are  built  of  brick  made  from  the  alluvial  clay  be- 
neath and  around  them.  In  Holland  and  the  other  provinces 
of  the  Netherlands,  where  no  stone  except  a  very  soft  and  in- 
ferior sandstone  is  found,  the  use  of  brick  as  the  chief  building 
material  became  almost  universal  from  earliest  times,  even  the 
paving  of  the  streets  and  other  public  works  being  done  with 
brick.  There  are  buildings  in  some  cities  of  the  Netherlands 
in  which  stone  has  been  largely  used,  but  they  are  the  excep- 
tion rather  than  the  rule. 

Peter  Mortier,  in  a  small  book  published  in  A.  D.  1782,  gives 
a  description  of, the  city  hall  of  Amsterdam.  He  says  that  the 
old  city  hall  was  erected  earlier  than  A.  D.  1400,  that  the  front 
and  sides  rested  on  divers  stone  columns,  and  that  on  one  side 
there  was  a  four-square  stone  steeple ;  that  the  building  was 


THE   HISTORY    OF   BRICK.  15 

burned  July  7,  A.  D.  1682,  and  the  heat  was  so  great  that 
everything  was  consumed  except  a  piece  of  brick-work  in  the 
steeple.  The  new  building  was  constructed  on  the  site  of  the 
old  one,  but  was  commenced  in  1684,  part  of  the  old  structure 
having  been  taken  down  to  make  room  for  the  new.  In  order 
to  obtain  a  foundation  for  the  new  building,  13,659  piles  were 
driven,  upon  which  were  placed  seven  feet  of  brick-work  to 
form  the  foundation. 

It  was  under  Wouter  Van  Twiller,  of  Amsterdam,  a  governor 
appointed  by  the  Dutch  West  India  Company,  that  the  first 
brick  buildings  were  erected  in  this  country.  In  1633,  soon 
after  his  arrival  on  Manhattan  Island,  Governor  Van  Twiller 
erected  for  his  own  use  a  substantial  brick  house,  which  was  the 
most  elaborate  private  dwelling  which  had  up  to  that  time  been 
attempted  in  America,  and  during  the  remainder  of  the  Dutch 
dynasty  this  dwelling  served  for  the  residence  of  the  successive 
chiefs  of  the  colony.  He  also  built  several  small  brick  dwell- 
ings for  the  officers,  which,  with  his  own,  were  erected  within 
the  walls  of  the  fort.  The  brick  used  in  these  buildings  were 
brought  from  Amsterdam,  and  wer^  of  such  a  good  quality 
that  but  few  were  broken  in  the  long  and  rough  voyage.  The 
Dutch  seem  to  have  succeeded  well  in  making  a  strong  and 
very  durable  quality  of  brick,  which  brick  have  been  famous 
from  an  early  period  for  soundness,  and  specimens  of  them 
brought  over  by  the  early  settlers  from  Holland  are  yet  to  be 
met  with  in  some  of  the  old  Dutch  houses  of  New  York. 

Among  the  Puritan  emigrants  to  New  England  money  was 
very  scarce,  and,  under  Winthrop,  carpenters  and  bricklayers, 
whose  services  were  in  great  demand,  and  had  a  monopoly 
price,  were  forbidden  to  accept  over  \2d.,  and  afterwards,  in 
1630,  2s.  per  day,  the  penalty  being  icxy.  to  giver  and  taker. 
The  bricklayers  were  also  the  stone-masons ;  they  ranked 
under  the  first  head,  but  a  much  larger  amount  of  building  was 
done  in  wood  and  in  stone  than  in  brick  in  those  times. 

The  earliest -settlement  in  this  country  in  which  brickmakers 
are  recorded  as  being  part  of  the  population  was  the  colony  of 


1 6  BRICK,  TILES   AND   TERRA-COTTA. 

New  Haven.  In  this  industrious  and  inventive  little  company 
it  is  probable  that  the  first  brick  made  in  this  country  were 
burned  in  1650.  They  had  no  rich  backers  willing  to  foot  the 
bills  for  costly  brick  buildings,  as  the  Dutch  West  India  Com- 
pany had  done  for  Governor  Van  Twiller  in  his  building  opera- 
tions at  Manhattan,  or  New  Amsterdam,  as  it  was  called  at  a 
later  period.  They  had  made  several  attempts  to  produce 
brick  at  earlier  times,  but  had  failed,  and  it  is  not  probable 
that  the  very  few  which  they  did  succeed  in  burning  were  of  a 
very  superior  quality.  But,  like  the  building  of  their  ship, 
which  sailed  from  their  ice-bound  shore  and  was  never  again 
heard  of,  though  faulty  in  many  respects,  their  production  was 
an  evidence  of  great  energy,  and  it  is  the  inheritance  of  this 
same  quality  that  has  made  all  that  section  of  country  a  great 
manufacturing  and  inventive  district. 

The  Virginia  colonists  possessed  clay  of  a  far  superior  qual- 
ity for  brick-making ;  but  they  do  not  seem  to  have  made  any 
attempt  to  utilize  it.  A  few  brick  were  brought  from  England 
and  used  in  the  furnaces  of  an  iron  foundry  and  a  glass-house, 
both  of  which  were  destroyed  during  the  great  massacre  of 
March,  1622,  and  appear  to  have  comprised  the  entire  manu- 
factures of  the  colony. 

Brick  has  been  a  choice  material  for  building  purposes  in  the 
State  of  Pennsylvania  from  its  primitive  days.  In  a  letter  from 
William  Penn  to  his  agent,  J.  Harrison,  as  Pennsbury,  written 
in  1685,  m  speaking  of  a  lady  who  had  purchased  land  and  in- 
tended to  emigrate,  he  said :  "  She  wants  a  house  of  brick,  like 
Hannah  Psalter's,  in  Burlington,  and  she  will  give  £40  sterling 
in  money  and  as  much  more  in  goods.  It  must  have  four 
rooms  below,  about  18x36  feet  large,  the  rooms  9  feet  high, 
and  two  stories  height."  Some  idea  of  the  great  purchasing 
power  of  money  in  those  days,  as  well  as  the  price  and  value  of 
buildings,  can  be  seen  from  the  above. 

In  1 705  the  price  of  bricklayer's  labor  in  Philadelphia  was 
3,y.  6d.  per  day,  and  the  price  of  brick  22s.  per  thousand.  One 
of  the  oldest  public  buildings  in  this  country  constructed  of 


THE    HISTORY    OF   BRICK.  17 

brick  was  the  old  court-house  in  the  city  of  Philadelphia,  com- 
menced in  the  fall  of  1705,  and  to  these  Pilgrim  Fathers  the 
erection  of  this  building  was  a  great  undertaking  and  their 
largest  endeavor.  Gifts,  fines,  assessments,  and  forfeitures  were 
all  combined  to  give  it  the  amplitude  of  a  "  Great  Towne 
House"  or  "Guild  Hall,"  as  it  was  sometimes  called  when  first 
built.  To  modern  ideas  this  building  was  small  and  ignoble ; 
but  in  those  days  it  was  grand  and  imposing  in  the  eyes  of  all 
the  populace.  The  total  expense  of  the  structure  was  £616, 
the  brick  costing  2gs.  6d.  per  thousand,  and  the  bricklaying 
costing  145.  per  thousand.  This  primitive  building  was  erected 
in  the  middle  of  High,  or  as  it  is  now  called,  Market  Street,  at 
the  corner  of  Second,  and  after  being  used  for  various  purposes 
for  one  hundred  and  thirty  years,  it  was  demolished  in  the 
spring  of  1837.  for  about  twenty-eight  years  it  was  used  as  a 
court-house ;  but  its  use  for  that  purpose  was  superseded  by 
the  erection  of  "  the  new  State-House,"  or  "  Independence 
Hall,"  as  it  is  now  called,  which  was  built  of  brick,  in  1733. 
Another  primitive  brick  building  in  that  city  was  the  "Great 
Meeting-house"  of  Friends,  at  the  south  of  the  "Great  Towne 
House,"  on  the  corner  of  Second  anS  High  streets.  This  build- 
ing and  the  surrounding  brick  walls  which  inclosed  it  were 
erected  in  1695,  the  ground  being  given  for  that  purpose  by 
George  Fox,  for  "truth's  and  Friends'  sake."  Early  in  1719 
brick  came  into  use  for  foot  pavements  in  Philadelphia,  and  the 
great  demand  for  them  made  the  material  very  expensive. 

Brick  do  not  appear  to  have  been  much  used  in  the  early 
buildings  of  Boston,  as  wood  seems  to  have  been  the  favorite 
material  for  building  purposes  with  the  Puritan  emigrants,  stone 
being  sometimes  employed.  The  first  "Towne  House "  erected 
in  Boston  was  constructed  of  wood;  it  was  built  about  1657, 
and  stood  at  the  head  of  State  street,  and  was  consumed  in  the 
great  fire  of  171 1.  Its  successor  was  a  brick  edifice,  erected  in 
1712,  on  the  same  spot,  which  in  turn  was  destroyed  in  the  fire 
of  1747.  The  "old  State-House"  was  built  the  next  year, 
1748,  and  as  late  as  1791  it  was  described  as  "an  elegant  brick 

2 


1 8  BRICK,  TILES    AND   TERRA-COTTA, 

building,  110  feet  in  length  and  38  in  breadth."  The  first 
Episcopal  church  in  Boston  was  erected  in  1689,  of  wood,  at  a 
cost  of  £284,  and  was  at  the  corner  of  Tremont  and  School 
streets.  The  "  Triangular  Warehouse,"  which  stood  at  the 
head  of  the  "towne  dock,"  was  one  of  the  earliest  brick  build- 
ings erected  in  Boston ;  it  was  built  by  London  merchants 
about  1700.  Its  foundation  was  of  stone  and  its  walls  of  brick, 
which  were  of  a  larger  size  than  the  brick  of  the  country  in 
later  times. 

Brick-work  became  common  in  this  country  in  the  early  part 
of  the  eighteenth  century,  and  until  the  trouble  between  the 
colonies  and  the  mother  country,  brick  were  imported  mostly 
from  England.  There  was  not  much  inducement  to  produce 
home-made  brick  previous  to  this  time,  as  vessels  sailing  with 
light  cargoes  for  the  colonies  would  finish  out  with  brick,  which 
commanded  ready  sales  at  moderate  prices,  rather  than  with 
stone  ballast,  which  would  have  to  be  thrown  overboard  before 
receiving  their  heavy  return  cargoes  of  tobacco  and  other  ex 
ports  of  the  colonies. 

In  this  way  a  number  of  brick  buildings  were  constructed  on 
the  tide  waters  of  the  Atlantic  coast,  in  the  times  which  pre- 
ceded the  troublesome  period  of  the  Revolution.  At  the  time 
immediately  following  this  war,  there  was  but  little  done  in  the 
line  of  building;  the  generally  distressed  condition  of  the  in- 
dustries and  the  finances  of  the  country  was  a  bar  to  any  im- 
provements except  such  as  were  in  the  nature  of  repairs  neces- 
sary to  make  buildings  habitable. 

The  condition  of  things  after  the  adoption  of  the  Constitu- 
tion gradually  changed ;  churches  and  other  buildings  of  a 
public  character,  which  had  remained  in  an  unfinished  state 
during  the  entire  period  of  the  war,  were  completed,  and  a  few 
houses  of  a  substantial  character  were  erected  in  some  portions 
of  the  country,  home-made  brick  being  generally  employed 
when  they  could  be  obtained,  and  the  character  of  the  build- 
ings admitted,  which  was  but  seldom,  as  wood  and  stone  en- 
tered largely  into  the  construction  of  the  great  proportion  of 
all  buildings. 


THE    HISTORY    OF   BRICK.  19 

The  inventive  genius  of  the  new  nation  was  not  much  stimu- 
lated to  improving  on  the  manner  of  the  mother  country  in  the 
production  of  brick.  In  fact,  those  which  we  then  made  were 
poorly  moulded  and  burned,  and  compared  unfavorably  with 
the  common  building  brick  of  English  and  Dutch  manufac- 
ture. But  at  the  present  time,  both  for  quantity  and  quality, 
we  have  no  equal  in  any  nation  of  the  world,  and  for  this  we 
are  largely  indebted  to  the  American  patent  system,  which 
greatly  fosters  and  encourages  development  in  this  line,  as  in 
other  and  kindred  arts. 

Improvements  in  modes  or  machines  for  manufacturing  com- 
mon brick  received  but  little  attention  until  about  1835  ;  Pre- 
viously  they  were  more  remarkable  for  being  unique  in  some 
special  point,  of  but  small  importance,  than  for  any  generally 
good  achievements ;  that  is,  no  attention  was  paid  to  the  re- 
sulting brick  after  it  came  from  the  kiln  ;  the  whole  idea  seemed 
to  be  to  shape  or  mould  it  in  some  manner.  For  instance,  one 
machine  was  made  like  a  box  now  used  by  plasterers  to  run 
off  their  lime;  it  was  elevated  slightly,  and  the  mud,  which 
was  mixed  in  the  box,  allowed  to  petes  through  a  grate  into  a 
large  framework  having  sides  about  three  inches  high,  and  di- 
vided by  wires  stretched  lengthwise  and  across  it,  which  lay 
upon  the  bottom,  and  when  the  clay  in  the  shallow  box  was 
somewhat  hardened,  the  wires  were  raised  and  the  brick  thereby 
cut  and  formed  into  shape.  The  box,  when  emptied  of  the 
clay,  could  be  easily  moved  on  wheels  running  on  a  plank 
gangway  to  the  next  shallow  mould-box,  and  so  on.  But  the 
slush  stock  made  in  this  way  was  very  inferior ;  it  would  dry 
unequally,  be  full  of  cracks,  and  was  subjected  to  no  packing 
as  in  the  pug-mill,  or  pressure  as  by  machines  of  to-day,  or  a 
blow  as  is  done  by  the  hand-moulder,  who  dashes  the  tempered 
and  packed  clay  into  the  mould  with  great  force,  and  again 
drives  it  down  and  closer  together  with  the  hands  and  plane. 
When  the  brick  came  from  the  kiln  they  were  light,  very  open 
or  porous,  therefore  absorbed  water  readily,  and  were  entirely 
unfit  for  building  purposes. 


20  BRICK,  TILES   AND    TERRA-CpTTA. 

The  mode  of  manufacturing  brick  has  been  revolutionized 
during  the  past  twenty  years,  and  it  seems  almost  like  a  mira- 
cle when  we  note  the  present  development  of  this  art  and  then 
recall  that  the  first  crude  brick  machine  which  was  made  in 
this  country  was  invented  in  1835  by  Nathaniel  Adams,  who 
died  at  Cornwall,  N.  Y.  The  machine  was  simply  a  hand- 
moulder;  but  he  afterwards,  about  1840,  invented  a  power 
machine.  It  proved  quite  successful,  and  a  few  of  them  are 
still  in  use.  Mr.  Adams  was  also  the  first  to  invent  and  use 
the  iron  tempering-wheel.  The  model  of  his  brick  machine 
may  still  be  seen  in  the  patent  office  at  our  National  Capital. 
It  is  related  that  in  the  4O's,  Mr.  Adams  undertook  to  establish 
a  brickyard  at  Philadelphia,  and  built  a  power  (horse-power, 
we  presume)  machine,  but  he  was  not  allowed  to  start  it,  as  a 
mob  destroyed  the  machine  and  drove  Mr.  Adams  and  his 
family  from  the  city.  They  took  refuge  in  Camden,  where  they 
remained  two  weeks  or  more,  until  the  workmen  had  quieted 
down  and  it  was  safe  for  them  to  return.  In  the  year  1840, 
many  of  the  people  in  Philadelphia  could  not  get  work  at  any 
price,  and  they  did  not  like  to  recognize  anything  which  they 
thought  would  take  the  physical  labor  out  of  their  own  hands. 
From  such  beginnings  has  our  business  grown,  until  now  ( 1 895  ) 
there  are  annually  consumed  in  the  leading  cities  of  this  coun- 
try the  following  mentioned  enormous  quantities  of  brick : 

New  York 1,100,000,000 

Chicago 600,000,000 

Philadelphia 450,000,000 

Boston 1 75,000,000 

St.  Louis 225,000,000 

Washington 150,000,000 

Omaha 100,000.000 

Cincinnati 100,000,000 

Cleveland 100,000,000 

Pittsburgh 100,000,000 


Total 3,100,000,000 

Brick-making  in  the   South,  and  especially  in  the  States  of 


THE    HISTORY    OF   BRICK.  21 

Texas,  Louisiana,  Mississippi  and  Florida,  and  also  in  Califor- 
nia, Oregon,  and  Washington,  has  within  the  past  ten  years 
not  compared  favorably  with  other  sections  of  our  country, 
the  reason  being  mainly  owing  to  the  railroads  developing 
immense  tracts  of  the  very  choicest  timber  lands,  thereby  en- 
couraging the  establishment  of  a  large  number  of  saw-mills, 
thus  affording  not  only  a  lighter  and  cheaper  building  material 
for  the  great  masses,  but  one  also  better  adapted  for  the  climate. 
But  this  tendency  to  frame  construction  is  liable  at  any  time  to 
cause  enormous  loss  from  fire,  as  diyiptrnns  conflagrations  are 
likely  to  occur  at  any  moment  either  in  New  Orleans  or  San 
Francisco,  eind  similar  cities  in  which  lumber  is  so  extensively 
used  as  a  building  material. 

The  enlarged  and  more  convenient  methods  of  making  brick, 
as  practised  in  the  vicinity  of  the  larger  cities  of  the  United 
States,  came  from  necessity  to  meet  the  increased  demand, 
owing  to  the  growing  of  our  building  interests  incident  to  the 
increase  of  our  population.  With  the  increased  demand  for 
building  material  in  the  eastern  and  northern  portion  of  the 
country  came  a  decrease  in  our  lumber  supply.  Something 
had  to  be  found  to  take  the  place  of  timber,  and  nothing  could 
be  so  serviceable  and  durable  as  brick,  or  that  would  withstand 
the  action  of  the  elements  so  well. 

During  the  past  twenty-five  years  there  has  been  created  a 
demand  for  road-way  paving  brick.  These  brick  differ  from 
building  brick  in  many  particulars.  The  best  of  them  do  not 
absorb  more  than  one  per  cent,  of  moisture,  and  are  very  hard 
— turning  even  a  steel  drill.  Over  300  cities  and  towns  have 
adopted  this  form  of  paving,  which  is  a  guarantee  of  its  success. 

The  most  popular  kind  of  paving  brick  at  present  is  the  so- 
called  vitrified  brick,  made  of  some  grade  of  shale.  These  are 
good  paving  material,  and  it  is  not  the  intention  to  say  anything 
to  their  discredit;  but  it  must  be  granted  by  their  friends  and 
advocates,  that  they  are  not  the  only  brick  that  make  good 
pavements.  Those  who  have  studied  the  history  of  brick  pave- 
ments the  most,  know  too  well  that  the  first  pavements  laid, 


22  BRICK,  TILES    AND   TERRA-COTTA. 

and  those  that  gave  brick  their  present  popularity  as  a  material 
for  street  pavements,  were  not  made  of  shale,  and  in  fact  many 
of  them  were  not  very  well  vitrified,  yet  they  have  stood  the 
test  of  nearly  a  quarter  of  a  century,  and  are  in  excellent  condi- 
tion to-day.  With  this  fact  patent  to  all,  the  present  fashion 
runs  after  the  shale  brick,  and  in  many  instances  engineers  in- 
sert in  their  specifications  the  requirement  that  the  brick  used 
in  paving  the  streets  of  their  cities  shall  be  of  this  class.  The 
motive  that  prompts  this  is  laudable,  and  the  engineers  doubt- 
less insert  it  in  all  sincerity ;  but  is  it  always  wise  and  for  the 
best  that  they  should  do  so?  Their  desire  is  to  get  the  best 
pavement  that  is  to  be  had,  and  fashion  says  that  brick  made 
of  shale  make  the  best. 

An  old  saying  declares  that,  "  Enough  is  as  good  as  a  feast." 
In  the  face  of  prejudice  and  inexperience,  the  early  brick  pave- 
ments have  wrung  from  the  minds  of  the  people  the  confession 
that  they  are  good  enough. 

Upon  this  basis  the  present  boom  in  brick  pavements  has 
been  built,  Is  it  not  then  not  only  an  injustice,  an  ingratitude, 
but  an  exhibition  of  arrogance,  for  the  shale  brick  to  claim  that 
it  alone  is  adapted  to  the  work  of  street  paving?  If  it  should 
happen,  as  it  often  does,  that  there  were  no  factories  working 
shale  near  the  city  to  be  paved,  but  good  paving  brick  made 
of  other  clays  could  be  obtained  near  and  at  less  expense  than 
those  made  of  shale,  it  would  not  be  right  to  specify  that  only 
brick  made  of  shale  should  be  used.  The  engineer  who  did 
this  and  required  his  patrons  to  bear  the  additional  expense 
would  not  be  a  faithful  servant  who  guarded  the  people's  inter- 
ests. All  of  this  goes  to  show  that  the  market  for  paving  brick 
is  so  largely  in  the  hands  of  interested  parties  as  to  make  it  an 
objectionable  feature  of  the  business. 

The  use  of  brick  for  street  pavements  has  only  come  into 
general  use  within  the  last  decade.  The  universal  prosperity 
of  the  country  during  that  time  has  made  it  possible  to  pave 
the  streets  of  many  towns  that  heretofore  had  been  neglected. 
Since  the  desirability  of  brick  for  this  purpose  has  been  estab- 


THE    HISTORY    OF   BRICK.  23 

lished  and  they  have  been  placed  upon  the  market  at  prices 
that  made  it  possible  to  improve  the  much  needed  but  long 
neglected  streets,  an  impetus  has  been  given  to  the  business 
that  is  almost  without  a  parallel  in  the  annals  of  the  industries. 

During  the  present  decade  there  have  been  two  classes  of 
streets  to  pave,  those  that  had  been  neglected  during  the 
growth  of  the  cities  for  many  years  past,  because  of  the  want 
of  a  suitable  material  for  the  work  at  prices  within  the  means 
of  the  cities  needing  pavements,  and  those  that  result  from  the 
growth  of  the  towns  during  the  decade. 

There  has  been  an  attempt  made  to  bring  the  work  of  paving 
up  to  the  times,  and  to  complete  the  work  according  to  the 
needs  of  each  city.  This  work  is  being  rapidly  carried  forward, 
and  whenever  it  is  accomplished  there  will  be  a  decline  in  the 
amount  of  paving  done  each  year,  and  this  amount  will  natur- 
ally become  adjusted  to  the  growth  of  the  country. 

For  further  information  on  the  subject  of  paving  brick  manu- 
facture, see  Chapter  VI. 

Some  of  the  hardest  and  most  durable  Iprick  which  have 
probably  ever  been  produced  in  the  world,  the  writer  saw  made 
in  a  few  hours  and  in  a  peculiar  manner  at  El  Paso,  Texas,  in 
November,  1887,  and  the  process  consisted  simply  of  running 
the  slag  as  it  came  from  the  smelting  furnaces  into  moulds  in 
which  they  were  formed  into  brick.  The  adoption  of  this  plan 
for  utilizing  slag  would  serve  a  two-fold  purpose,  and  it  would 
do  away  with  the  necessity  of  finding  vacant  ground  for  the 
constantly  increasing  accumulations  of  this  material,  and  also 
be  a  source  of  profit  to  the  smelter,  as  the  brick  manufactured 
would  be  indestructible,  hard  as  steel,  and  finely  finished. 

The  business  of  manufacturing  brick,  like  any  other  calling, 
demands,  in  the  present  age  of  machinery  and  competition,  the 
closest  attention  and  personal  supervision,  even  to  details,  in 
order  to  insure  success ;  and  the  measure  of  prosperity  is  small 
to  the  brick-maker  whose  heart  is  not  in,  and  whose  mind  is 
not  upon  his  business.  In  this  craft  there  is  no  sentiment;  on 
the  contrary,  the  brick-maker's  life  is  one  of  laborious  applica- 


24  BRICK,  TILES   AND   TERRA-COTTA. 

tion,  unremitting  watchfulness,  with  large  and  constantly  in- 
creasing responsibilities.  From  the  moment  the  clay  is  dug  in 
the  bank  to  the  time  the  brick  is  delivered  to  the  building, 
there  is  not  a  single  step  or  move  but  which  demands  the  in- 
dividual supervision  and  exacts  the  watchful  eye  and  constant 
care  of  the  brick-maker  who  expects  and  desires  success. 
Before  long  the  old-time  typical  brick-yard,  with  its  primitive 
outfit,  will  become  a  tradition  of  the  past,  and  will  have  scarcely 
a  place  in  our  memories.  It  has  answered  the  purpose  for 
which  it  was  designed,  has  performed  its  part  in  the  building 
and  improvement  of  this  marvellous  land.  In  the  earlier  strug- 
gles of  the  people  of  this  country  to  provide  shelter  and  homes 
for  their  families,  it  has  filled  no  unimportant  place.  Up  to 
within  a  few  years  the  hand-brickmaker  did  not  recognize  the 
logic  of  wants,  or  yield  to  the  restless  genius  of  the  minds  en- 
gaged in  the  persistent  purpose  of  inventing  machinery  that 
would  make  a  better  brick  cheaper  than  could  be  made  by 
manual  process.  We  cannot  blame  him  if  he  still  loves  the 
sound  of  the  walk  dropping  in  the  mould,  the  peculiar  smell 
of  the  poplar  slider,  and  the  cracking  of  the  pen-mouth  fire, 
all  of  which  have  a  charm  for  the  old  time  hand-brickmaker. 

The  brick-machines  which  will  be  hereafter  enumerated  have 
indeed  revolutionized  the  craft  in  almost  every  particular. 
With  every  mechanical  device  which  is  to  be  described  in  this 
volume  I  am  perfectly  familiar,  and  have  seen  all  in  actual 
operation,  and  for  this  reason  have  selected  such  for  illustrating 
the  different  portions  of  this  work.  There  are  other  contriv- 
ances and  machines  made  in  this  country  and  in  Europe,  that 
may  be  equally  as  good  as  some  herein  given,  and  no  effort 
will  be  made  to  praise  those  which  shall  be  used  for  illustra- 
tions above  others  which  may  have  equal  claims  for  considera- 
tion. The  thousands  of  inventions  cannot  all  be  mentioned ; 
and  rather  than  fall  into  a  sea  of  error,  so  common  in  mechan- 
ical descriptions,  I  shall  be  compelled  to  select  only  those  the 
merits  or  demerits  of  which  I  can  discuss  from  personal 
knowledge. 


THE    HISTORY    OF   BRICK.  25 

Before  any  attempt  is  made  to  explain  the  processes  or  ma- 
chines employed  in  the  manufacture  of  brick  or  the  other 
branches  of  pottery,  it  is  highly  important  that  there  should 
be  a  thorough  knowledge  of  the  character  of  clay,  and  some  of 
its  changes  while  under  the  several  conditions  to  which  it  is  to 
be  subjected.  This  will  be  attempted  in  a  general  way  for 
brick  in  the  following  chapter. 


CHAPTER   II. 

CLAY. 

BUILDING  BRICK  CLAYS  ;    HUDSON  RIVER  CLAYS  ;    PAVING  BRICK  CLAYS  ;  FIRE- 

CIAYS  ;    METHOD  OF  ANALYSIS  FOR  FIRE-CLAYS,  FELDSPARS, 

KAOLIN,  AND  FIRE  SANDS  ;   TERRA-COTTA  CLAYS  J 

KAOLIN  OR  CHINA  CLAY. 

UNDER  the  general  term  clay  many  varieties  are  included 
which  are  more  or  less  used  in  the  arts  and  manufactures.  The 
characteristic  property  of  clay,  and  one  possessed  by  no  other 
mineral  substance,  is  that  peculiar  condition  known  as  plastic. 
The  ingredient  of  clays  to  which  this  feature  is  due  is  a  hydrous 
silicate  of  alumina.  When  pure  it  is  of  a  snow-white  color ;  to, 
the  touch  it  has  a  soft  unctuous  feeling,  and  is  very  easily 
broken ;  it  adheres  to  the  tongue  and  gives  off  a  singular  smell 
when  breathed  upon,  which  has  been  designated  the  argillaceous 
odor.  When  moistened  with  water  a  considerable  quantity  of 
the  fluid  is  absorbed,  and  upon  manipulation  the  clay  speedily 
passes  into  the  plastic  condition,  which  enables  it  to  be  molded 
into  many  different  forms. 

The  purest  clay  found  in  nature  is  known  by  the  technical 
name  of  kaolin,  or  China  clay. 

The  word  "  Clay  "  is  derived  from  the  Anglo-Saxon  Claeg ; 
Dutch,  Klei ;  German,  Kleben,  which  means  "  to  stick." 

In  addition  to  sand,  there  are  also  compounds  present  in 
clays  which  often  have  an  important  bearing  in  determining  their 
economic  value.  Among  these  are  iron  pyrites,  sulphate  of 
lime,  carbonate  of  lime,  dolomite,  carbonaceous  and  bituminous 
matter,  oxide  of  iron,  etc.  To  these  are  due  the  various  colors 
which  characterize  ordinary  clays,  and  which  vary  in  their  effect 
upon  the  material  when  it  is  applied  to  technical  purposes.  .  In 
geological  works  clays  are  divided,  in  accordance  with  their 

(26) 


CLAY.  27 

occurrence,  into  primary  and  secondary  deposits.  From  their 
physical  conditions  of  structure  and  chemical  composition,  clays 
are  technically  separated  into  various  classes,  expressed  by  the 
words  fat,  long,  lean,  short,  plastic,  argyllites,  clay-slates,  marls 
and  loams. 

From  chemical  and  mechanical  considerations  it  is  evident 
that  the  major  portion  of  the  insoluble  residue  left  after  the  de- 
composition of  feldspathic  rocks  cannot  be  pure  kaolin,  but 
must  necessarily  be  a  mechanical  mixture  of  it,  with  more  or 
less  partly  altered  feldspar  and  the  most  easily  decomposed 
materials  of  the  original  rock,  with  a  certain  proportion  of 
quartz.  This  material  in  the  past  has  been  deposited  in  the 
depressions  on  the  earth's  surface,  and  in  changes  due  to  the 
unstable  condition  of  the  earth's  crust  was  subjected  to  heat 
and  pressure  and  became  consolidated,  forming  a  true  rock. 
This,  in  turn,  was  upheaved  by  the  internal  forces  of  the  earth, 
and  was  again  subjected  to  disintegrating  influences. 

Among  the  materials  forming  clay  are  various  minerals  con- 
taining protoxide  of  iron  ;  these,  under  atmospheric  action, 
become  altered  to  higher  states  of  oxidation,  and  give  to  the 
clays  all  shades  of  color  from  the  finest  yellow  to  the  deepest 
brown  ;  they  also  explain  why  pure  white  kaolin  is  so  seldom 
found.  This  disintegration  of  the  primitive  rocks  and  the 
rocks  that  were  formed  from  them,  going  on  through  millions 
of  years,  has  resulted  in  a  deposition  in  nature's  settling  tanks 
of  vast  amounts  of  clay  of  more  or  less  purity.  They  occur  in 
beds  of  varying  thickness,  and  follow  the  stratification  in  dips 
and  strike  of  the  underlying  rock.  These  primary  deposits  of 
clay  have  been  rearranged  many  times  by  subsequent  geolog- 
ical changes,  which  have  had  effect  in  redispositions  of  these 
clays,  and  sometimes  resulted  in  the  purification  of  the  clay 
mineral  proper,  and  at  other  times  in  its  degeneration. 

The  power  to  pass,  with  water,  into  a  dough-like  plastic 
state,  decreases  in  proportion  as  a  sandy  element  is  mixed  with 
the  clay.  It  is  strongest  in  the  "fat"  and  weakest  in  the 
"lean"  clays.  A  "fat"  clay  dries  very  slowly  and  unevenly, 

'E  LlB 

OF  THE 

UNIVERSITY 


CALIFORNIA 


28  BRICK,  TILES   AND   TERRA-COTTA. 

and  the  molded  objects  will  warp  and  crack  in  drying.  Aron 
found  that  the  "  linear  shrinkage"  does  not  correspond  with 
the  drying  of  the  clay,  as  might  be  expected,  but  ceases  when 
followed  up  to  a  certain  point,  which  he  designates  as  the 
"  limits  of  shrinkage."  The  water  evaporated  up  to  this  point, 
he  terms  the  "water  of  shrinkage;"  the  remainder  of  the  water 
lost,  until  the  weight  of  the  sample  remains  constant  at  a  tem- 
perature of  266  degrees  F.,  he  calls  the  "water  of  pores;"  the 
sum  of  both  is  total  water. 

If  we  assume  that  the  minute  particles  of  clay  substance 
possess  the  round  shape  claimed  by  Dr.  Koenig,  this  behavior 
is  easily  explained,  as  the  "  water  of  shrinkage  "  envelops  these 
particles,  and  upon  evaporation  will  allow  them  to  approach, 
until  each  touches  the  other  at  six  points  on  the  surface.  The 
intervals  between  all  other  points  will  still  be  filled  with  "water 
of  the  pores;"  and  its  evaporation  cannot  produce  any  shrink- 
age of  the  clay.  Now,  Dr.  Koenig  claims  that  it  is  an  important 
rule  for  the  potter  that  the  number  and  sizes  of  the  pores  are 
independent  of  the  water  contained  in  the  clay,  and  is  constant 
for  all  plastic  clays ;  and,  further,  that  the  cubical  shrinkage  is 
equal  to  the  volume  of  water  lost  by  evaporation  up  to  the  limit 
of  "  linear  shrinkage."  Aron  contends,  further,  that  if  the  pur- 
est clay  is  mixed  with  fine  quartz  sand,  the  shrinkage  will  in- 
crease up  to  a  certain  point,  which  he  terms  the  "  point  of 
greatest  density."  From  this  point  the  shrinkage  decreases 
again,  with  increasing  leanness,  while  the  porousness  increases. 
On  submitting  clay  to  a  red  heat,  two  molecules  of  water  are 
driven  off  from  the  silica  of  alumina  at  that  temperature,  and, 
as  a  result,  the  clay  shrinks  a  second  time.  This  is  known  as 
the  "  fire  shrinkage,"  and  can  be  neutralized  by  the  addition  of 
finely-divided  sand,  and  may  even  be  made  to  produce  a  slight 
expansion.  Finely  pulverized  chalk  is  also  an  excellent  mater- 
ial to  counteract  the  "fire  shrinkage"  in  clays. 

The  ordinary  yellow  brick  clays  contain  iron  in  the  state  of 
oxide  and  carbonate  chemically  combined  with  water,  forming 
what  are  known  in  chemistry  as  hydrates.  The  expulsion  of 


CLAY.  29 

this  water  in  the  process  of  burning  imparts  a  red  color,  due 
to  the  conversion  of  the  hydrated  oxides  of  iron  into  the  an- 
hydrous form.  The  principal  constituent  in  brick  clay,  and 
that  upon  which  its  plasticity  depends,  is  the  chemical  combi- 
nation of  silica  and  alumina,  more  particularly  described  under 
the  head  of  "  Kaolin."  This  constituent  used  alone  shrinks 
and  cracks  in  drying,  warps  and  becomes  very  hard  when 
baked.  Silica  is  also  present  in  nearly  all  clays  in  an  uncom- 
bined  state,  such  as  sand.  A  proper  proportion  of  sand  pre- 
vents cracking,  shrinkage  and  warping,  and  furnishes  silica 
necessary  for  a  partial  fusion  of  the  materials  which  increases 
the  strength  of  the  brick.  The  sand  also  makes  the  brick 
more  shapely  and  equable  in  texture  ;  but  an  excess  of  sand 
in  clay  renders  the  brick  made  from  it  too  brittle.  A  small 
quantity  of  carbonate  of  lime  has  a  beneficial  effect  upon  brick 
clay  in  two  ways — it  lessens  the  contraction  of  the  newly-made 
brick  in  drying,  and  acts  as  a  flux  in  the  kiln  by  the  formation 
of  silicate  of  lime,  which  binds  the  particles  together.  It  is 
evident  from  this  that  an  excess  of  carbonate  of  lime  in  the 
clay  would  cause  the  brick  to  melUand  lose  its  shape.  Iron 
pyrites  in  a  brick  clay  are  objectionable ;  also  the  presence  of 
carbonaceous  matter  to  any  considerable  extent,  as  a  black 
discoloration,  similar  to  that  produced  in  brick  in  proximity  to 
chimney  flues,  is  likely  to  occur. 

Common  salt  is  nearly  always  present  in  minute  quantities 
in  clay.  In  that  near  the  seashore  the  amount  is  apt  to  be  so 
great  that  brick  made  from  it  are  certain  to  be  of  a  poor  qual- 
ity. Salt  melts  readily  and  glazes  the  outside  of  the  brick,  and 
the  heat  cannot  be  raised  or  maintained  sufficiently  long  to 
burn  them  to  the  core,  or  into  good  hard  brick ;  as  a  conse- 
quence they  are  soft,  and  from  the  presence  of  the  decomposed 
salts  of  magnesia  and  soda,  are  always  damp,  owing  to  the 
tendency  of  these  salts  to  absorb  moisture  from  the  atmosphere. 
The  presence  of  the  alkaline  carbonates  in  clay  to  any  notable 
extent,  prevents  its  being  used  as  a  brick  clay,  the  alkali  caus- 
ing the  material  to  melt  readily. 


3O  BRICK,  TILES   AND   TERRA-COTTA. 

Rare  minerals  containing  such  metals  as  cobalt,  copper, 
zinc,  and  such  salts  as  phosphate  of  iron,  are  met  in  clays,  but 
are  exceptions  and  are  of  no  importance  in  practical  work. 
Thus  it  appears  that  mineralogically,  clays  are  kaolinite,  mixed 
with  sand,  colored  by  iron  and  organic  matter,  and  showing 
varying  amounts  of  feldspar,  mica,  and  other  silicates  and 
titanates.  The  chemical  investigation  of  a  clay  should  en- 
deavor to  present  these  facts,  besides  grouping  those  bodies 
together  which  are  similar  in  action  and  effect. 

BUILDING  BRICK  CLAYS. 

Brick-makers  divide  clays  into  three  classes : 

First.  Plastic  or  strong  clays,  which  are  chiefly  a  silicate  of 
alumina,  which  are  by  the  workmen  called  "  foul  clays ;  "  a 
more  fitting  name,  and  one  by  which  they  are  also  called,  is 
"  pure  clay." 

Second.  Loams  and  mild  clays  are  those  in  which  there  is 
a  considerable  proportion  of  sand  intermixed. 

Third.  Marls  or  calcareous  clays  are,  as  their  name  indi- 
cates, clays  containing  a  notable  quantity  of  carbonate  of  lime. 

"  Malm  "  is  the  name  applied  by  English  brick-makers  to  an 
artificial  marl,  made  by  adding  to  and  intermixing  with  the  clay 
a  proper  proportion  of  carbonate  of  lime. 

As  a  general  rule,  a  clay  fit  for  the  manufacture  of  a  first- 
class  quality  of  building-brick  is  not  met  with  in  nature.  There 
is  almost  always  a  deficiency  of  sand  and  lime.  A  good  brick 
clay  is  one  that  contains  sufficient  fusible  elements  to  bind  the 
mass  together,  but  not  so  much  as  to  make  the  brick  adhere  to 
each  other  or  become  vitrified.  Such  clays  contain  from  20  to 
30  per  cent,  alumina,  and  50  to  60  per  cent,  silica,  the  re- 
mainder consisting  principally  of  carbonates  of  lime  and  mag- 
nesia, and  oxide  of  iron. 

Pure  or  "foul  clays"  are  sometimes  used  for  brick  without 
any  admixture  of  substances  to  improve  the  material.  Brick 
thus  made  are  generally  deficient  in  weathering  qualities.  The 
color  of  brick  depends  upon  the  composition  of  the  clay,  the 


CLAY.  3 1 

character  of  the  added  ingredients,  the  temperature  at  which 
they  are  burnt,  and  the  amount  of  air  admitted  to  the  kiln.  A 
clay  free  from  iron  will  burn  white,  but  as  a  general  rule  car- 
bonate of  lime  (in  the  form  of  chalk)  is  added  to  produce  white 
brick.  The  presence  of  iron  oxides  produces  a  tint  which 
varies  from  light  yellow  to  dark  red,  the  intensity  of  color  in- 
creasing with  the  greater  quantity  of  the  oxide.  If  8  or  10  per 
cent,  of  iron  oxide  is  present,  and  the  brick  becomes  intensely 
heated,  the  red  oxide  of  iron  combines  with  the  silica  and  fuses, 
producing  a  dark- blue  or  purple  color.  The  presence  also  of  a 
small  quantity  of  oxide  of  manganese,  in  addition  to  the  oxide 
of  iron,  will  cause  a  material  darkening  of  the  red  tint.  By  the 
presence  of  small  quantities  of  lime  the  red  color  of  iron  oxide 
is  modified  to  a  cream  tint,  while  larger  quantities  make  a 
brown  color.  Magnesia  also  changes  the  red  tint  to  yellow. 

In  the  clays  from  which  the  famous  Milwaukee  cream-colored 
brick  are  made,  the  proportion  of  lime  and  magnesia  runs  up 
to  twenty-three  per  cent,  carbonate  of  lime,  and  seventeen  per 
cent,  carbonate  of  magnesia,  with  nearly  five  per  cent,  of  iron. 
The  average  brick-clays  of  the  drift  sfyow  from  three  to  ten  per 
cent,  of  lime,  and  in  these  uses  it  is  a  valuable  agent,  but  it 
would  be  quite  fatal  to  any  of  the  higher  uses  of  clay.  The 
alkalies,  i.  e,,  potash,  soda  and  lithia,  are  found  in  all  clays  to 
greater  or  less  extent,  though  not  all  together  by  any  means. 
Potash  is  most  common  and  most  detrimental,  lithia  is  most  in- 
frequent and  in  the  smallest  amounts.  Its  presence  has  not 
heretofore  been  noticed  as  an  element  in  Ohio  clays,  but  once 
detected,  it  was  found  in  a  number  of  samples.  Mention  has 
been  made  of  mica  and  feldspar  as  the  probable  sources  of  the 
alkalies  in  clays,  and  this  theory  is  strengthened  from  the  fact 
that  the  largest  source  of  lithia  at  present  is  one  of  the  minerals 
of  the  mica  group,  viz.,  lepidolite. 

The  knowledge  of  the  composition  and  properties  of  clay 
now  current  among  the  clay  manufacturers,  is  almost  wholly 
practical,  and  there  may  seem  to  be  ground  for  surprise  that 
such  excellent  results  should  have  been  obtained  with  so  little 


32  BRICK,  TILES   AND   TERRA-COTTA. 

aid  from  science,  but  it  is  to  be  remembered  that  much  less  has 
been  done  for  this  subject  than  for  parallel  industries.  The 
scientific  research  directed  to  it  is  much  more  scanty  in  pro- 
portion to  the  interest  involved  than  in  almost  any  similar  field. 

What  work  has  already  been  done  has  proved  very  valuable, 
and  further  study  cannot  but  be  productive  of  good. 

Clay,  as  we  have  seen  from  the  foregoing  description,  instead 
of  being  a  mineral  formed  by  the  ordinary  processes  of  chem- 
ical synthesis,  is  the  result  of  decomposition  of  granite  rocks, 
or  by  a  closer  definition,  is  the  result  of  the  decomposition  of 
feldspars  or  those  rocks  which  yield  them,  notably  granitic  and 
gniessic  rock.  Orthoclase,  the  feldspar  from  which  the  body  of 
our  clays  is  derived,  is  a  double  silicate  of  potash  and  alumina ; 
the  other  feldspars  found  accompanying  it  are  albite,  or  the 
soda  feldspar,  and  oligoclase,  the  soda-lime  feldspar ;  these 
latter  forms  are  in  small  proportion  compared  to  orthoclase. 
Ordinary  aqueous  and  atmospheric  agencies  are  sufficient  to 
decompose  feldspar,  giving  rise  to  hydrated  silicate  of  alumina 
or  kaolin  and  a  soluble  salt  of  potash,  which  is  carried  away  by 
the  water  which  accompanies  decomposition.  Feldspar  beds 
are  fruitful  sources  of  the  finest  kaolins  and  china  clays,  and  are 
rarely  found  without  some  kaolin  accompanying. 

The  mineral  elements  in  granite  and  gneiss,  as  is  familiar  to 
all,  are  quartz,  feldspar  ancT  mica.  The  first  mineral  is  not 
affected  by  air  or  water,  but  the  feldspars,  and  to  some  small 
extent  the  micas,  are  attacked  by  the  atmosphere.  When  the 
feldspar  decomposes,  the  bond  which  holds  the  other  elements 
together  is  gone,  and  the  quartz  and  mica  are  carried  off  by 
water  or  mixed  with  the  clay  in  varying  proportions,  as  the 
conditions  of  formation  vary.  The  more  the  water  carries  off 
the  purer  the  clay  left  behind. 

The  irregularity  of  composition  which  is  so  characteristic  of 
clay,  is  thus  seen  to  be  the  result  of  the  differing  mechanical 
conditions  which  surround  the  clay  as  it  forms ;  it  is  distinct- 
ively a  mineral  in  which  other  forces  than  chemical  affinity 
have  left  their  mark ;  and  another  element  of  uncertainty  is 


CLAY.  33 

added  in  the  fact  that  if  the  mechanical  conditions  were  con- 
stant, clays  would  vary  with  the  parent  rock,  which  has  no 
fixed  structure. 

Thus  is  exposed,  in  the  origin  of  clay,  the  reason  of  that 
irregularity  which  has  so  long  baffled  or  retarded  progress  in 
its  study,  but  which  once  understood,  proves  the  key  to  all  that 
follows. 

The  qualifications  for  a  clay  for  building  brick  are  simple, 
viz. :  Plasticity  when  wet,  and  solidity  and  hardness  when 
burned. 

Clays  containing  a  large  amount  of  carbonaceous  matter 
naturally  mixed  with  it  are  very  objectionable,  as  brick  when 
made  from  such  clays  will,  when  wetted  in  the  wall,  pass  out 
soluble  compounds,  which  discolor  the  walls,  whether  they  are 
painted  or  not,  and  plastering  or  stucco-work  is  discolored  by 
them  the  same  as  when  brick  which  have  once  been  used  in 
the  inside  of  a  chimney  flue  and  become  blackened,  are  re-used 
in  new  work. 

It  would  be  useless  to  attempt  decorative  work  of  any  de- 
scription upon  brick  walls,  the  materials  of  which  contain  a 
large  amount  of  carbonaceous  matter,  or  if  the  brick  be  made 
from  the  alluvial  mud  of  the  embouchures  of  rivers,  as  no  pos- 
sible precaution  can  prevent  the  entire  destruction  of  the  work. 

Carbonate  of  lime,  diffused  limestone  and  lime  pebbles,  when 
they  are  present  in  brick  clays,  are  a  decided  hindrance  to  the 
production  of  even  a  passable  quality  of  building  brick,  for  in 
the  kiln  the  limestone  and  lime-pebbles  are  converted  into 
caustic  lime,  and  when  the  brick  are  used  below  ground,  or 
for  exposed  walls,  the  moisture  and  carbonic  acid,  which  pene- 
trate to  every  part  of  a  brick,  slack  the  nodules  of  lime,  the 
swelling  causing  the  brick  to  burst  and  break  to  pieces. 
Should  such  brick  be  used  for  "  filling  in,"  or  inside  or  unex- 
posed  walls,  the  dampness  from  the  mortar  used  in  laying 
them,  and  also  that  contained  in  the  plastering,  would,  by  pro- 
ducing the  same  bursting  and  breaking,  destroy  the  finished 
face  of  the  inside  walls. 
3 


34  BRICK,  TILES   AND   TERRA-COTTA. 

These  are  some  of  the  evils  which  result  from  the  badly-made 
brick  so  freely  used  in  Chicago,  and  arise  from  the  large 
amount  of  lime-pebbles  in  the  clay,  and  the  neglect  of  finely 
pulverizing  or  thoroughly  sifting  the  clay,  which  can  easily  be 
done  by  machinery,  at  but  a  small  additional  cost. 

Selecting  Clays  for  Various  Kinds  of  Building- Brick.  Brick 
of  uniform  quality  can  be  made  from  low  grade  clays,  but 
good,  salable,  uniform  building-brick  require  that  suitable  clay 
shall  be  used  in  their  manufacture ;  the  better  the  grade  of 
brick  produced  the  more  remunerative  the  price  which  they 
command  in  the  market.  If  common  mud-brick  are  to  be 
manufactured  by  the  hand  method  of  moulding  and  without  the 
use  of  machinery  for  crushing  the  clay  preparatory  to  pugging, 
a  clay  should  be  selected  that  is  very  tender  and  easily  soaked 
and  pugged.  The  pugging  qualities  of  clays  can  be  determined 
by  digging  and  pugging  a  small  pit  full  of  the  material.  The 
plasticity,  as  well  as  the  moulding  and  drying  qualities  of  clays, 
can  also  be  readily  tested  on  a  similar  small  scale.  There  is  no 
better  way  for  determining  the  color  to  which  a  clay  will  burn 
than  by  making  and  burning  the  brick  in  a  test  kiln,  such  as 
several  of  the  leading  brick  machinery  manufacturers  of  the 
country  maintain  for  testing  purposes  at  their  factories.  Clays 
manufactured  into  a  few  brick  and  sent  to  a  neighboring  kiln  to 
be  burned  and  tested  for  color  often  turn  out  unsatisfactorily, 
for  the  reason  that  different  clays  burned  in  the  same  kiln  tend 
to  impart  a  uniform  color  to  each  other. 

If  the  brick  are  to  be  manufactured  by  the  soft-clay  process 
almost  any  kind  of  material  can  be  used  that  will  hold  its  shape 
in  drying.  Clays  such  as  the  Hudson  river  clays,  which  are 
largely  impregnated  with  quicksand  will  not  retain  their  shape, 
in  drying  if  they  are  too  much  pugged,  hence  the  brick- 
machines  used  in  the  Hudson  river  district  do  not  have  too 
great  a  pugging  power  for  the  clays. 

Both  the  stiff-clay  and  dry-press  brick  machines  require  for 
their  successful  operation  a  strong  plastic  clay.  Fine  front  or 
pressed-brick  require  clays  having  all  the  qualities  necessary 


CLAY.  35 

for  good  common  brick  and  in  addition  the  color-producing 
qualities.  Iron  is  generally  supposed  to  be  the  all-important 
constituent  necessary  to  produce  a  good  red  color,  but  there 
are  a  number  of  things  and  conditions,  besides  the  iron,  that  are 
necessary  for  the  successful  manufacture  of  the  best  classes  of 
salable  front  brick. 

The  iron  should  be  equally  distributed  throughout  the  mass 
to  be  burned.  The  lack  of  ability  to  do  this  successfully  has 
caused  many  attempts  at  artificial  coloring  of  clays  to  prove 
failures.  The  clays  must  be  of  such  a  nature  as  will  enable 
them  to  stand  sufficient  heat,  without  warping  and  twisting,  to 
bring  out  the  color.  They  should  also  be  without  those  ele- 
ments which,  when  brought  to  a  high  temperature,  unite  with 
the  iron  and  carry  it  out  of  the  brick  and  kiln  in  the  form  of 
vapor.  An  analysis  which  shows  a  good  per  cent,  of  iron  in 
clay  does  not  always  prove  that  the  brick  will  burn  a  good  red 
color. 

Clays  which  shrink  a  great  deal  are  not  the  best  for  front- 
brick  making,  as  they  are  liable  to  warp  and  crack  in  burning. 

Such  clays  are  more  liable  to  show-  stripes  and  brown  edges 
than  those  that  shrink  less. 

In  erecting  works  for  the  manufacture  of  building-brick,  it  is 
necessary  first  to  determine  whether  the  clay  located  upon  the 
property  is  suitable,  not  only  in  its  nature,  but  in  the  quantity 
present.  The  digging  of  one  or  two  pits  will  not  determine  the 
question.  Examinations  should  be  made  by  boring  into  the 
earth  in  a  large  number  of  places.  This  is  an  expeditious  and 
general  method,  and  it  is  possible  by  boring  to  penetrate  all 
the  strata  or  beds  of  clay  on  the  property.  Large-size  boulders 
cannot  be  thus  penetrated,  and  layers  of  gravel  are  also  hard  to 
penetrate,  while  wet  sand,  such  as  quick  sand,  also  offers  im- 
pediments ;  these  obstacles,  however,  are  usually  of  no  great 
extent,  and  by  making  different  trials  can  almost  always  be 
avoided.  There  are  a  variety  of  augers  and  bits  used  in  mak- 
ing explorations  of  clay  by  boring. 

The  specimens  of  clay  brought  to  the  surface  by  the  boring- 


36  BRICK,  TILES    AND   TERRA-COTTA. 

auger  are  usually  fair  specimens,  disclosing  as  they  do,  not  only 
the  character,  but  the  thickness  of  the  strata  from  which  they 
are  taken.  Of  course  the  number  of  borings  to  be  made  will 
be  governed  somewhat  by  the  information  obtained  from  the 
clays  brought  to  the  surfaces.  If  the  strata  seems  to  be  of  al- 
most uniform  depth  and  thickness,  a  less  number  of  borings 
will  be  required  than  when  less  uniformity  of  the  clay  forma- 
tions is  shown  to  exist. 

HUDSON    RIVER    BRICK    CLAYS. 

The  deposits  of  brick  clay  extend  along  both  sides  of  the 
Hudson  river  more  or  less  continuously  from  Sing  Sing  to  Al- 
bany, N.  Y. 

There  are  isolated  patches  below  the  former  locality  but  they 
are  not  of  any  great  extent.  There  are  two  narrow  portions  of 
the  river  from  Staatsburgh  to  New  Hamburgh,  and  from  Corn- 
wall to  Jones'  Point,  where  little  clay  is  found. 

The  embankment  in  which  the  clay  lies  often  rises  steeply 
from  the  shore  and  the  terrace  which  the  clay  underlies  extends 
in  some  cases,  especially  along  the  upper  portions  of  the  river, 
one  or  more  miles  from  the  shore,  while  at  other  localities  is 
not  over  400  to  500  feet  wide.  In  speaking  of  the  terrace  ex- 
tending back  several  miles,  it  is  not  meant  in  an  unbroken 
stretch,  for  numerous  ridges  of  rock  project  above  its  surface  at 
many  localities. 

The  thickness  of  the  clays  is  also  very  variable,  they  being 
underlain  by  irregular  ridges  of  rock,  and  rounded  hills  of 
stratified  drift  or  kames,  or  as  at  Verplanck  and  Cruger's,  the 
clay  lies  in  basins  scooped  out  in  the  rock  by  the  ice. 

On  the  average,  the  clay  is  of  good  quality,  and  capable  of 
producing  a  good  brick.  The  Croton  Point  clays,  and  portions 
of  those  below  Peekskill  are  very  "  fat."  By  a  fat  clay  is  meant 
one  possessing  great  plasticity  and  being  quite  pure.  Again, 
at  other  localities,  as  New  Winsdor  and  Haverstraw,  the  clay 
contains  numerous  patches  of  quicksand.  These  patches  are 
generally  flat  and  lie  parallel  to  the  clay  layers. 


CLAY.  37 

There  is  hardly  a  clay-bank,  however,  which  does  not  show 
streaks  of  quicksand. 

Two  kinds  of  clay  are  found  along  the  river,  the  blue  and  the 
yellow ;  the  former  always  underlies  the  latter,  and  occasionally 
they  shade  into  each  other  or  are  interstratified. 

As  to  the  relative  qualities  of  the  two,  the  blue  makes  a  better 
brick,  and  does  not  shrink  so  much  in  drying  and  burning  as 
the  yellow.  The  yellow  gives  a  better  colored  brick,  is  tougher 
than  the  blue,  does  not  occur  in  as  great  quantity  and  is  not  as 
plastic.  At  some  yards  only  the  yellow  is  used ;  at  others, 
only  the  blue. 

The  Hudson  river  clays  are,  with  few  exceptions,  situated  so 
as  to  afford  the  greatest  ease  and  economy  of  working.  The 
yards  are  mostly  located  along  the  river  front,  the  clay  bank 
being  adjacent  to  them,  and  at  a  higher  level,  so  that  the  haul- 
age of  the  clay  is  down  grade  to  the  tempering  pits. 

Though  occurring  usuallly  in  terraces,  still  the  presence  of  a 
terrace  does  not  always  indicate  clay.  For  instance,  at  Haver- 
straw  the  clay  is  obtained  from  the  sixty  feet  terrace,  while  the 
100  feet  one  is  composed  of  glacial  drift  and  delta  material. 
In  prospecting  for  clay  along  the  Hudson  river  there  is  little 
difficulty  in  detecting  its  presence.  It  can  generally  be  seen 
on  the  face  of  the  terrace  escarpment,  in  road-cuttings,  or  in 
the  sides  of  gullies  made  by  small  streams,  which  drain  the  ter- 
race. In  some  cases  the  surface  consists  of  sand  or  gravel,  and 
then  has  to  be  pierced  by  the  auger  in  order  to  determine  the 
presence  and  the  thickness  of  the  clay.  In  determing  the  ex- 
tent and  thickness  at  any  particular  locality,  it  is  of  importance 
to  make  a  number  of  borings,  as  sometimes  the  clay  suddenly 
thins  out.  When  the  terrace  is  narrow  the  clay  usually  thins 
out  as  it  recedes  from  the  river.  Unfortunately,  as  far  as  as- 
certainable,  few  borings  have  been  made  in  these  clays  to  deter- 
mine their  thickness,  and  in  most  cases  they  have  not  been 
mined  below  the  level  of  the  yard,  which  is  generally  eight  to 
ten  feet  above  mean  tide. 


38  BRICK,  TILES   AND   TERRA-COTTA. 

PAVING-BRICK    CLAYS. 

The  problem  to  be  solved  in  the  production  of  street-paving- 
brick  is  principally  that  of  compounding  clays,  or  of  selecting 
clays  with  a  special  view  to  manufacturing  tough  vitrified  brick. 

In  a  large  number  of  localities  in  the  United  States  there  are 
shale  clays  which  are  by  nature  specially  adapted  to  the  manu- 
facture of  vitrified  brick  for  street-paving  purposes.  But  all 
localities  in  which  a  market  exists  for  such  brick,  and  where  it 
is  desired  to  make  the  brick  for  roadway  paving,  are  not  so 
favored,  and  in  such  places  the  question  of  the  proper  selection 
and  mixture  of  materials  as  will  result  in  producing  a  hard, 
tough,  street-paving  brick  is  the  all-important  one. 

It  is  not  possible  to  make  good  brick  for  roadway  paving 
from  any  and  all  kinds  of  brick  earth.  Dirt  and  clay  mixed, 
and  mixtures  of  sand  and  fire-clay,  and  fire-clay  and  ordinary 
building-brick  clays  will  not  make  satisfactory  paving-brick. 
Mr.  J.  H.  Calkins,  of  Galesburg,  111.,  in  speaking  of  this  subject, 
says :  "  The  result  of  trying  to  make  pavers  out  of  poor  clay 
will  be  a  failure.  To  make  good  pavers  you  want  to  select  a 
clay  which,  by  giving  it  a  hard  burn,  will  melt  together  like 
iron,  so  that  not  a  particle  of  water  can  soak  into  it,  and  which 
can  not  be  even  marred  by  a  steel  drill.  When  you  have 
found  such  a  clay,  thoroughly  pulverize  it,  make  a  stiff  mixture 
with  water,  and  mould  your  brick  on  a  machine  with  an  end 
pressure.  Get  all  the  clay  into  the  brick  that  you  possibly  can 
do;  dry  as  other  brick,  only  give  them  a  harder  burn." 

Mr.  W.  A.  Eudaly,  Cincinnati,  Ohio,  says:  "The  idea  of 
using  a  number  one  fire-clay  for  paving-brick  is  a  mistake. 
What  I  mean  by  a  number  one  fire-clay  is  such  as  Mount 
Savage  clay,  or  what  we  in  the  West  compare  to  a  Mount  Sav- 
age clay.  Such  clays  are  of  no  use  for  paving-brick.  They 
will  not  vitrify,  and  when  burned  have  no  strength ;  will  not 
stand  the  frost,  but  crumble  and  fall  to  pieces  with  the  action 
of  frost  and  wear.  A  low  grade  of  fire-clay,  however,  will 
make  an  excellent  paving-brick,  for  the  reason  that  it  will  stand 
a  high  degree  of  heat  in  burning,  and  yet  can  be  vitrified,  and 


CLAY.  39 

is  usually  strong  and  tough  when  well  burned.  Most  low 
grades  of  fire-clay  possess  this  quality  of  toughness,  hence  the 
idea  that  fire-clay  must  be  used  for  paving-brick.  You  can 
often  get  paving-brick  by  mixing  number  one  fire-clay  with 
common  clay,  providing  the  latter  will  also  stand  a  high  degree 
of  heat  in  burning.  You  run  the  risk,  however,  of  making  a 
brittle  brick,  as  you  are  likely  to  burn  the  life  out  of  the  com- 
mon clay  before  the  fire-clay  has  been  affected  by  the  heat." 

Mr.  F.  E.  Frey,  Willoughby,  Ohio,  in  this  connection  says : 
"  I  have  some  experience  in  the  mixing  and  manipulation  of 
different  clays  for  the  manufacture  of  street-paving-brick.  I 
have  seen  it  done  at  Columbus,  Ohio,  where  they  have  a  shale 
clay  like  fire-clay.  By  itself  it  will  not  make  a  good  brick,  but 
by  mixing  it  with  sand  and  a  kind  of  red  clay  having  iron  in  it, 
it  makes  a  good  paving-brick.  In  fact,  it  makes  an  artificial 
flint,  and  by  the  time  it  is  burned  it  is  the  same  as  flint,  as  you 
cannot  break  it.  You  can  readily  cut  glass  with  it.  It  makes  a 
fine  material  for  paving  purposes  by  proper  manipulation  with 
different  clays.  In  that  way  you  can  make  a  good  paving 
brick  when  otherwise  perhaps  you  can  not." 

Mr.  Shea,  of  Decatur,  111.,  who  has  had  a  large  experience 
in  manufacturing  street  paving-brick  from  common  clay,  and 
who  has  succeeded  in  producing  a  hard,  tough,  flinty  brick, 
gives  his  ideas  on  the  subject  in  the  following  language :  "  I 
admit  you  must  have  an  intense  heat  to  make  a  paving-brick, 
but  it  is  not  necessary  to  have  anything  pertaining  to  fire-clay. 
The  further  away  you  can  go  from  fire-clay,  in  my  opinion,  the 
better  brick  you  will  have.  The  clay  that  will  make  paving- 
brick  is  not  as  scarce  as  one  might  imagine.  There  is  a  great 
deal  of  paving-brick  clay  all  over  the  country,  and  it  will  be 
discovered  as  the  demand  for  paving-brick  arises." 

Mr.  W.  D.  Gates,  of  Chicago,  111. :  "  Do  not  give  up  your 
clays  too  quickly ;  do  not  make  up  your  mind  too  quickly  that 
you  cannot  make  paving-brick,  It  may  be  that  just  the  little 
item  of  tempering  the  brick  in  the  kiln  may  change  failure  to 
success.  A  man  that  has  clay  that  does  not  fuse  easily,  that 


40  BRICK,  TILES   AND   TERRA-COTTA. 

stands  a  high  heat,  no  matter  whether  it  is  fire-clay  or  not,  has 
a  fruitful  field  for  experiment  before  him." 

Mr.  A.  O.  Jones,  of  Zanesville,  O. :  "  The  majority  of  good 
building-brick  clays  with  different  treatments  will  make  fairly 
good  paving-brick  for  light  travel.  But  to  stand  the  wear  and 
traffic  of  large  cities,  and  to  equal  granite  and  other  high-priced 
and  expensive  pavements,  there  must  be  a  careful  selection  of 
clays,  such  as  semi-fire-clays  or  some  of  the  shale  clays  that 
will  stand  a  high  degree  of  heat  so  as  to  become  thoroughly 
vitrified,  and  at  the  same  time  have  the  toughness  that  is  neces- 
sary to  stand  the  continuous  friction  of  heavy-loaded  teams 
from  and  to  the  freight  stations  and  wharves. 

"We  have  on  our  property  a  36-foot  vein  of  potters'  clay,  or 
clay  of  the  semi-fire  clay  nature.  Owing  to  the  ability  of  this 
clay  to  stand  intense  firing,  we  commenced  mixing  it  with  a 
variety  of  clays  which  we  have,  the  idea  being  to  secure  such  a 
mixture  of  materials  as  would  result  in  the  production  of  a 
thoroughly  vitrified  brick,  suitable  in  every  way  for  the  paving 
of  public  roadways.  After  a  variety  of  experiments,  we  finally 
secured  a  mixture  of  clays  which  under  intense  heat  made  a 
paving-brick  of  great  strength  and  toughness." 

Mr.  George  S.  Tiffany,  of  Tecumseh,  Mich.,  in  speaking  of 
the  manufacture  of  vitrified  street  paving-brick,  said  :  "  I  could 
tell  you  the  best  way  to  make  vitrified  brick,  but  the  question 
at  the  root  of  the  matter  is :  What  clay  will  make  the  best  pav- 
ing brick?  I  can  only  answer  that  question  by  saying  that  the 
clay  must  be  ascertained  by  experiment  and  trial.  The  differ- 
ences in  clays  are  just  as  infinite  as  the  characters  of  men.  Of 
fire-clays  there  are  a  vast  number  of  varieties,  some  of  which 
clays  possess  scarcely  any  refractory  power.  There  are  clays 
that  are  called  common  clays  that  are  superior  in  refractory 
power  to  some  clays  that  are  called  fire-clays.  A  clay  that 
will  make  good  sewer  pipe  is  good  clay  from  which  to  make 
vitrified  brick.  In  the  process  of  vitrification,  you  want  to  stop 
just  before  the  process  is  completed.  At  that  point  it  is  liable 
to  go  into  the  molten  state  and  your  whole  kiln  come  down 


CLAY.  41 

upon  your  hands.  You  must  ascertain  by  the  most  careful  ex- 
periments, if  you  attempt  to  make  vitrified  paving-brick,  how 
high  you  can  set  your  brick,  or  else  you  will  endanger  your 
whole  kiln  and  lose  thousands  of  dollars  by  foolish  trials. 

"  There  are  many  of  our  surface  clays  that  are  simply  de- 
composed shale  which  has  become  plastic  clay  under  atmos- 
pheric action.  Such  clays  take  the  salt-glaze  as  a  general 
thing  best.  They  have  the  proper  elements,  containing  suffi- 
cient silica  and  iron,  and  they  are  free  from  infusorial  earth, 
lime,  etc.  Take  a  clay  that  will  rapidly  effervesce  under  the 
action  of  acids,  and  you  cannot  get  any  kind  of  a  glaze  upon  it, 
and  I  suggest  the  acid  test  to  you  before  you  make  any  other  ex- 
periments. You  can  also  judge  something  by  observation  of  the 
effect  of  fire  upon  your  own  kilns  of  brick,  whether  you  have  any 
prospect  of  making  paving-brick.  If  the  heads  of  your  arches 
— if  the  under  brick,  the  key  brick  are  glazed,  that  is  an  en- 
couraging sign.  There  was  a  friend  of  mine  asked  me  not  long 
since  to  visit  his  yard.  He  wanted  to  talk  with  me  about  put- 
ting in  a  stiff-mud  machine  to  make  paving-brick.  I  went  to 
see  him.  Of  course  I  wanted  to  seevhis  kilns  and  his  clays,  es- 
pecially his  clays.  I  went  out  to  the  yard  and  we  examined 
the  burned  brick  in  the  kiln.  They  were  removing  the  brick 
and  he  took  out  a  brick  from  the  arch  and  showed  it  to  me. 
One  end  of  that  brick  was  burned  to  a  good  hard  heat  with  no 
sign  of  vitrification  whatever. 

"  The  other  end  of  that  brick  was  burned  and  shriveled  out  of 
shape.  Now,  there  was  not  a  point  between  the  two  ends  that 
had  the  elements  of  a  vitrified  brick  that  was  in  a  fit  condition 
as  a  body  for  a  paving-brick.  There  are  a  thousand  such  cases 
all  over  the  country.  It  is  absurd  for  any  one  to  attempt  to 
make  paving-brick  from  clays  of  that  kind." 

Brick  for  roadway  paving,  as  will  be  seen  by  the  foregoing 
description  of  the  clay  to  be  used  in  their  manufacture,  are  en- 
tirely different  from  common  brick.  Clay  for  such  brick 
should  be  able,  without  fusing,  to  withstand  a  sufficient  degree 
of  heat  and  for  a  long  time,  to  render  the  brick  hard  and  im- 
pervious to  water. 


42  BRICK,  TILES    AND   TERRA-COTTA. 

Lime,  magnesia  and  the  alkalies  in  the  clay  render  it  fusible, 
and  they  are  to  be  avoided  :  iron,  beyond  6  to  10  per  cent.,  if 
the  clay  is  silicious,  also  renders  it  fusible.  Silica  and  alumina 
constitute  the  refractory  parts  of  brick,  and  the  other  parts 
named,  the  fluxing  part. 

From  the  experience  of  the  leading  manufactures  of  paving- 
brick,  it  is  concluded  that  fineness  of  grain  is  most  essential. 
When  fine-grained  clay  has  a  hard,  compact  structure,  no  pains 
should  be  spread  to  reduce  it  in  a  dry  state  to  an  impalpable 
powder. 

When  the  clay  is  neither  dry  nor  fine,  but  of  desired  com- 
position, it  may  be  calcined  and  then  finely  ground. 

The  clay  used  at  Galesburg,  111.,  is  of  a  shale  formation  and 
is  known  as  soapstone.  It  lies  near  the  surface  of  the  hills, 
and  varies  in  depth  from  fifty  to  nearly  three  hundred  feet.  It 
is  almost  free  from  grit,  and  when  pulverized  and  moistened  it 
is  sticky  or  doughy  in  the  fingers.  A  lump  taken  fresh  from 
the  bank  without  crushing  or  drying  takes  water  very  slowly, 
and  if  rubbed  on  a  smooth  surface  before  drying  will  present  a 
slick,  glassy  or  oily  surface. 

The  Diamond  Brick  Company,  of  Kansas  City,  Mo.,  exploits 
a  clay  similar  to  the  clays  above  described,  except  that  it  is 
found  at  a  depth  of  from  fifty  to  two  hundred  feet  below  the 
surface,  and  is  therefore  mined  by  driving  entries  and  drifts  the 
same  as  coal  is  mined.  The  texture  of  this  clay  is  very  fine. 
It  is  almost  free  from  grit,  and  can  be  polished  with  a  smooth 
surface  when  taken  fresh  from  the  bank.  In  the  green  state,  or 
fresh  from  the  bank,  it  is  darker  than  that  found  at  Galesburg. 

The  clay  at  Atchison,  Kan.,  is  also  classed  among  the  soap- 
stone  clays,  and  is  very  similar  to  the  three  above-mentioned, 
except  that  it  runs  from  a  light  gray  to  a  dark  gray  in  the 
bank.  It  also  has  a  slight  trace  of  sand  or  grit,  and  does  not 
polish  quite  so  smooth  when  green.  It  vitrifies  at  a  high  de- 
gree of  heat,  and  stands  up  well  under  fire. 

At  Sioux  City,  Iowa,  the  clay  is  also  found  in  very  high 
bluffs.  Viewed  from  a  distance,  it  resembles  more  the  appear- 


CLAY.  43 

ance  of  large  or  thick  layers  of  stone  than  either  of  the  former 
clays.  The  physicial  appearance  of  these  clays  is  different 
from  all  other  clays  that  we  have  seen.  In  its  natural  state  it  is 
very  hard  and  dense.  Has  quite  a  per  cent,  of  sand,  also 
streaks  of  a  semi-fire-clay.  The  clay,  when  dry,  becomes  very 
hard ;  it  does  not  have  so  much  of  the  oily  or  soapy  appear- 
ance. It  requires  very  heavy  machinery  to  handle  it  properly, 
and  is  one  of  the  hardest  clays  to  burn  I  have  seen.  It  stands 
well  under  the  fire  and  makes  a  very  superior  paving-brick. 

The  clay  at  Des  Moines,  Iowa,  is  very  similar  to  the  Sioux 
City  clay  in  this :  that  it  possesses  quite  a  per  cent,  of  sand 
and  fire-clay.  We  do  not  wish  to  convey  the  idea  that  the  sand 
and  fire-clay  are  mixed  or  in  the  same  vein,  for  they  are  not, 
either  at  Des  Moines  or  Sioux  City ;  but  at  both  places  the  clay 
bank  is  very  high,  having  a  working  face  of  from  fifty  to  one 
hundred  feet,  and  in  both  the  sand,  clay  and  semi-fire-clay  lie 
in  pockets  and  different  layers. 

The  Des  Moines  clay  is  more  plastic  in  the  natural  state  than 
any  other  similar  clays  ;  in  fact,  it  is  found  almost  soft  in  portions 
of  the  bank,  while  in  other  portions  it  is  quite  hard  and  dense. 
This  clay  also  requires  a  very  high  degree  of  heat,  and  stands 
up  well  in  the  kiln,  and  produces  among  the  best  paving-brick 
in  the  market. 

Before  passing,  we  would  say  that  neither  the  Des  Moines 
nor  the  Sioux  City  clays  polish  in  the  green  state  so  readily  to 
a  smooth  surface,  and  when  burned  do  not  break  with  quite  so 
smooth  or  gloosy  a  fracture  as  some  other  clays. 

At  Middleport,  Ohio,  Garrett  &  McManigal  are  manufactur- 
ing excellent  paving-brick  from  a  deposit  made  at  some  time, 
no  doubt,  by  the  Ohio  river.  This  clay  is  plastic  in  the  bank, 
has  no  resemblance  whatever  to  soapstone  or  shale,  is  taken 
out  of  a  flat  field  near  the  surface.  It  has  very  little  sand. 
When  soaked,  becomes  sticky  and  tough  to  the  touch,  shrinks 
considerably  in  burning,  but  stands  up  well  under  fire.  Most 
brick-men  would  pronounce  this  a  number  one  red  brick  clay ; 
in  fact,  the  company  was  largely  engaged  in  making  dry 
pressed  brick  before  going  into  the  paving-brick  business. 


44  BRICK,  TILES   AND   TERRA-COTTA. 

At  Westerville,  Ohio,  Mr.  J.  W.  Emerald  is  making  paving- 
brick  from  a  clay  which  in  appearance  seems  to  be  nothing 
more  or  less  than  a  surface  clay.  We  do  not  mean  soil.  The 
clay  is  very  dark,  almost  black.  It  is  very  plastic  and  can  be 
handled  easily  with  the  spade,  almost  free  from  sand.  This  is 
a  remarkable  clay,  one  that  few  would  ever  suspect  as  suitable 
for  paving-brick,  but  teaches  that  paving-brick  material  can  be 
found  in  the  swamps  and  marshes  as  well  as  in  the  hills  and 
bluffs. 

The  above  descriptions  are  intended  to  aid  to  some  extent 
in  the  identification  of  paving-brick  clays  from  their  physical 
appearance. 

The  Bucyrus  Brick  &  Terra  Cotta  Co.,  of  Bucyrus,  Ohio,  use 
a  shale  clay  in  the  manufacture  of  their  vitrified  street  paving- 
brick,  which  is  of  an  exceptionally  fine  quality.  The  analysis 
of  this  shale  is  as  follows : 

Parts  in  100,000 — 
Metric  System  of  Weights. 

Silica 66.66 

Alumina 19.20 

Iron  Oxide — triple 6. 1 8 

Magnesia  Carbonate none. 

Organic  Matter none. 

Lime  Carbonate 0.72 

Free  Oxide  Alumina * 7.24 


100.00 


The  analysis  of  the  shale  from  which  the  vitrified  brick  are 
made  and  used  in  Fort  Smith,  Ark.,  as  given  by  the  State 
Geologist  of  Arkansas,  is  as  follows : 

Per  Cent. 

Silica .  58.43 

Alumina 22.50 

Oxide  of  Iron 8.35 

Magnesia 1.14 

Potash 2.18 

Soda 1.03 

Sulphur 1.16 

Loss  on  Ignition 6.20 

100.99 


CLAY. 


45 


The  Cambria  Iron  Company,  of  Johnstown,  Pa.,  has  dis- 
covered that  the  shale  which  is  taken  from  its  ore  mines  will 
make  a  superior  quality  of  vitrified  street  paving-brick.  The 
shale  taken  from  the  ore  mines  and  dumped  over  the  bank  was 
thought  to  be  entirely  worthless  until  this  discovery  was  made. 
Hundreds  of  thousands  of  tons  of  this  shale  are  lying  within 
several  miles  of  Johnstown. 

The  Grape  Creek  Clay  Company,  Grape  Creek,  111.,  in  the 
manufacture  of  its  street  paving-blocks,  uses  a  shale  clay  which 
is  found  overlaying  its  coal  measures  at  a  depth  of  120  feet  and 
1 60  feet  respectively. 

The  clay  on  leaving  the  mines  is  more  like  rock  than  clay. 

Shale  alone  makes  a  good  paving-brick  and  will  never  wear 
out  by  attrition.  Fire-clay  alone,  as  usually  worked,  possesses 
a  grainy  nature ;  when  put  in  the  pavement,  will  not  sustain  the 
amount  of  traffic  without  wear  that  is  desirable. 

The  London  Clay  Company,  of  London  Mills,  111.,  make 
paving-brick  of  shale  and  potter's  clay  in  such  proportions  as 
to  get  good  results.  The  potter's  clay,  withstanding  a  high 
temperature,  allows  great  latitude  in  the  burning  without  mak- 
ing the  brick  unshapely  by  melting  or  twisting  ;  while  the  shale, 
being  less  refractory,  melts  and  forms  a  union  of  all  the  mass, 
yet  being  relieved  of  their  glossy  nature,  making  them  tough, 
and  capable  of  resisting  the  action  of  frost,  and  maintaining  a 
smooth  surface  in  the  pavement. 

FIRE-CLAYS. 

Clays  are  termed  fire-clays  or  refractory  clays,  when  they  re- 
sist exposure  to  a  high  temperature  without  melting  or  becom- 
ing in  a  sensible  degree  soft  and  pasty.  These  clays  differ 
much  in  degree  of  refractory  quality.  They  occur  in  various 
geological  formations,  old  as  well  as  recent ;  but  some  of  the 
best  abound  in  the  coal-measures. 

All  clays  as  they  occur  in  nature  consist  essentially  of  hy- 
drous silicate  of  alumina,  and  upon  the  presence  of  the  water 
of  combination  depends  their  fictile  or  plastic  property ;  that  is, 


46  BRICK,  TILES   AND   TERRA-COTTA. 

their  capability  of  being  moulded  into  vessels  or  other  objects 
when  mixed  with  water  and  kneaded  to  a  pasty  consistency. 
All  clays  contain  hygroscopic  water,  which  may  be  expelled  at 
1 00°  C.  without  lessening  their  plasticity.  When,  however, 
clay  is  heated  to  redness,  it  loses  not  only  its  hygroscopic 
water,  but  also  its  water  of  combination,  and  as  a  consequence, 
it  ceases  to  be  plastic.  In  this  dehydrated  state  it  cannot  di- 
rectly combine  with  water  and  regain  its  plasticity,  though  it 
may  absorb  water  with  avidity.  Pounded  brick,  for  example, 
which  is  dehydrated  clay,  may  absorb  a  considerable  quantity 
of  water,  yet  without  regaining  the  slightest  degree  of  plas- 
ticity. 

It  is  important  to  note  that  there  may  be  great  variation  in 
the  composition  and  quality  of  clay  from  contiguous  beds  in 
the  same  pit,  and  even  from  the  same  continuous  horizontal 
bed  in  the  same  locality. 

If  we  compare  different  clays  together  in  respect  to  elemen- 
tary composition,  we  find  the  relation  between  the  silica  and 
alumina  to  be  extremely  variable ;  and  accordingly,  the  for- 
mulae which  have  been  proposed  to  express  their  rational  con- 
stitution are  very  discordant.  This  is  in  great  measure  to  be 
explained  by  the  fact  that  in  many  clays  a  large  proportion  of 
silica  exists  uncombined  either  in  the  form  of  sand,  or  in  much 
finer  state  of  division.  The  grittiness  of  clay  is  due  to  the 
presence  of  sand. 

Geologically  speaking,  fire-clays  are  of  three  distinct  forma- 
tions, viz.,  cretaceous,  the  carboniferous  or  coal  measures, 
tertiary ;  and  they  are  all  used  in  the  manufacture  of  fire-brick. 
The  first  and  the  last  of  these  are  both  of  them  soft  and  plastic. 
The  coal  measures  produce  both  plastic  and  non-plastic,  but 
the  plastic  is  neither  soft  nor  friable,  like  the  other  formations. 
On  the  contrary,  it  is  quite  hard  when  freshly  mined,  though  it 
always  lacks  the  clean-cut  fracture  characteristic  of  the  non- 
plastic. 

Fire-clays  are  of  many  colors,  black,  dark  and  light  gray, 
blue,  light  green,  white,  both  clear  and  deepening  into  a  bluish 


CLAY.  47 

or  grayish  tint.  The  flint  or  non-plastic  clays  are  sometimes 
clear,  of  various  shades,  other  times  spotted,  again  of  a  dark, 
almost  of  "a  chocolate  color,  with  veins  running  through  it,  and 
very  beautiful.  The  different  kinds  of  fire-clay  vary  so  much 
in  hardness  that  while  one  is  dug  with  a  spade,  another  has  to 
be  blasted  in  the  same  manner  as  rock  is  quarried. 

There  are  two  distinct  varieties,  non-plastic  or  flint  clay  and 
plastic  clay.  The  former  is  the  most  refractory.  They  are 
often  found  in  the  same  vein  and  interchangeably  as  regards 
position.  It  is  difficult  to  understand  how  it  happens  that 
some  clays  exist  in  this  flint-like  condition,  and  that  they 
should  be  so  much  more  refractory  than  the  other,  found  in  the 
same  vein,  and  perhaps  of  identical  composition.  The  fact  is, 
however,  that  the  more  plastic  any  clay  becomes,  either  natur- 
ally or  artificially,  the  less  refractory  it  is. 

In  the  United  States,  superior  qualities  of  fire-clays  are 
found  in  various  localities. 

In  the  majority  of  instances  fire-brick  plants  are  located 
upon  the  land  from  which  the  clays  are  taken.  There  are,  how- 
ever, some  notable  exceptions  to  this  rule.  The  works  of  the 
celebrated  fire-brick  manufacturers,  The  Harbison  &  Walker 
Co.,  are  located  in  the  city  of  Pittsburg,  Pa.,  while  the  fire- 
clays which  they  employ  are  drawn  from  various  parts  of  the 
state  of  Pennsylvania.  The  fire-clays  found  at  Mount  Savage, 
Md.,  the  "Amboy"clay  of  New  Jersey,  and  the  fire-clays  of 
Farrandsville,  Pa.,  are  all  highly  esteemed,  and  are  among  the 
best  fire-clays  found  in  America.  The  "  Amboy"  fire-brick  are 
produced  from  a  cretaceous  clay,  which  is  first  burned  in  a 
kiln,  its  plasticity  being  lost  in  the  process,  and  resulting  in 
what  is  known  as  "  cement."  The  second,  or  Mt.  Savage  brick, 
are  produced  from  two  qualities  or  varieties  of  carboniferous 
fire-clay,  one  of  which  has  in  its  natural  state  the  properties  of 
the  "  cement"  just  mentioned. 

At  Mineral  Point,  Tuscarawas  County,  Ohio,  and  at  New 
Lisbon,  Ohio,  a  clay  nearly  similar  to  the  Mt.  Savage  clay  is 
found ;  its  appearances  and  properties  are  about  the  same;  it  is 
non-plastic,  and  is  treated  in  the  same  manner. 


48  BRICK,  TILES    AND   TERRA-COTTA. 

For  all  these  clays  the  "  cement"  is  coarsely  ground,  mixed 
with  from  one-sixth  to  one-tenth  plastic  clay,  gradually  dried 
and  tempered,  and  then  hard-burned. 

The  fire-brick  made  from  the  clay  from  the  coal-measures  of 
Kentucky,  Pennsylvania,  Ohio,  Illinois  and  Missouri,  are  also 
held  in  high  esteem. 

The  following  is  an  analysis  of  Farrandsville,  Pa.,  fire-clay, 
by  J.  Blodget  Britton,  Iron-Master's  Laboratory,  Philadelphia, 
December,  1878:  — 

Silica 45.26 

Alumina 37.85 

Sesquioxide  of  iron 2.03 

Lime 08 

Magnesia .02 

Potash 1.26 

Water  and  organic  matter 13.30 

Oxide  of  manganese  and  loss .20 

100.00 

Mount  Savage  Clay.  In  the  year  1841  the  Mount  Savage 
Fire-Brick  and  Iron  Company  of  Mount  Savage,  Md.,  was  or- 
ganized, which  name  was  changed  in  1870  to  the  Union  Min- 
ing Company  of  Allegany  County,  Md. 

Mount  Savage,  Md.,  is  located  at  the  foot  of  Savage  moun- 
tain, nine  miles  north  of  Cumberland,  Md.,  on  the  line  of  the 
Cumberland  and  Pennsylvania  railroad.  The  Mount  Savage 
fire-brick  have  achieved  a  national  reputation  for  their  excellent 
qualities  for  use  in  blast  furnaces,  rolling-mills,  steel  plants  and 
gas  furnaces.  Analysis  of  Mass.  Inst.  of  Technology : 

Silica 50457 

Alumina 35-9O4 

Protoxide  Iron i  .504 

Lime 133 

Magnesia .018 

Potash trace 

Water  and  Organic  Matter 1 2.774 

Another  analysis : 


CLAY.  49 

Silica 48.95 

Alumina 35-33 

Protoxide  Iron 1.44 

Lime 34 

Magnesia .07 

Potash trace 

Water 13.90 

A  great  many  analyses  of  this  clay  have  been  made  at  vari- 
ous times  and  by  different  chemists,  but  it  would  not  be  safe  to 
take  any  one  of  the  results  as  a  test,  for  the  difference  in  them 
is  probably  due  as  much  to  the  chemists  as  to  the  samples. 
The  following  is  an  average  of  several  results,  which  will  prob- 
ably give  as  accurate  an  analysis  as  one  could  obtain : 

Silica 55.75 

Alumina 33-23 

Impurities 2.06 

Water 10.37 

The  bed  of  clay  lies  at  the  very  bottom  of  the  coal-measures 
of  this  basin.  On  top  of  the  clay  lies  an  8-inch  bed  of  coal ; 
beneath  it  lies  from  3  to  4  inches  of  shale ;  and  then  comes  the 
conglomerate  rock  which  marks  the  baundary  of  this  basin. 
The  bed  of  clay  varies  from  8  to  20  feet  in  thickness. 

The  clay  is  divided  into  two  varieties,  the  hard  and  the  soft; 
and  these  are  distinguished  by  their  physicial  properties.  One 
of  these  varieties  is  of  a  medium  gray  color,  shading  almost 
to  black.  This  clay  is  very  hard,  and  rattles  like  crockery 
when  thrown  into  the  chutes.  It  has  a  distinct,  though  not 
regular,  conchoidal  fracture ;  it  is  non-plastic  unless  ground  to 
an  impalpable  powder,  and  does  not  crumble  much  when  ex- 
posed to  the  weather  in  heaps,  being  affected  for  only  about  3 
or  4  inches  from  the  surface,  though  exposed  for  years.  In 
parts  of  the  mine  this  clay,  when  finally  broken,  is  sharp 
enough  to  cut  one's  hands. 

The  other  variety  is  a  very   plastic   clay,   of   much   lighter 
color,  weathering  very  rapidly,  and  in  one  season's  exposure 
crumbling  to  powder. 
4 


5O  BRICK,  TILES   AND   TERRA-COTTA. 

The  peculiarity  of  this  deposit  is,  that  the  two  clays  are  so 
intermixed  in  the  same  bed,  and  in  such  a  way,  that  in  the 
present  development  of  the  mine  there  is  no  accounting  for  the 
difference  in  structure  of  the  clay.  In  one  place  the  bed  will 
be  full  from  roof  to  floor  of  hard  clay,  and  in  another  place, 
within  a  few  feet  of  the  former,  the  clay  will  all  be  soft.  These 
sudden  changes  cannot  be  accounted  for.  Usually,  the  soft 
clay  lies  on  top  of  the  hard,  and  acts  as  a  sort  of  protector  for 
it,  keeping  off  the  coal  water.  In  some  places,  again,  there  is 
a  gradual  change  from  one  to  the  other,  from  hard  to  soft  and 
back  again ;  and  often  the  hard  clay  lies  between  layers  of  the 
soft.  This  is  what  causes  the  difficulty  in  the  mining  work  and 
makes  it  seem  irregular;  for  where  the  hard  clay  is  struck 
small  pillars  and  large  chambers  are  made,  and  vice  versa. 

The  impurities  in  this  clay  are  much  the  same  as  in  all  other 
clays,  except  that  they  are  fewer  and  smaller  in  amount. 
There  are  some  balls  of  iron  ore  found  in  the  bottom  of  the  bed, 
but  these  can  readily  be  seen.  The  most  objectionable  impur- 
ity is  iron  pyrites,  which  is  found  in  the  slips  of  the  soft  clay, 
and  particularly  in  the  casts  of  roots  in  that  variety.  The  de- 
tection of  these  iron  pyrites  is  impracticable  until  after  the 
brick  have  been  subjected  to  the  intense  heat  of  the  kiln,  when 
discoloration  is  shown  in  spots  on  their  surfaces. 

As  will  be  seen  on  reference  to  the  analyses,  one  great  reason 
for  the  superior  quality  of  the  Mount  Savage  clay  is  its  un- 
usual freedom  from  potash,  one  of  the  worst  constituents  of 
fire-clay ;  the  valuable  properties  of  fire-clay  being  reduced  in 
ratio  to  the  larger  percentage  of  potash  which  the  clay  may 
contain. 

Robert  Anderson  Cook,  A.  M.,  who  was  employed  by  the 
Union  Mining  Company,  of  Mount  Savage,  Md.,  in  making 
such  tests  as  seemed  to  be  desirable  to  keep  the  brick  up  to 
the  best  form  for  any  change  which  might  take  place  in  the 
market,  says :  "  It  was  not  intended  that  other  clays  should  be 
brought  to  mix  with  those  found  here;  and  from  tests  made 
here  of  brick  from  other  places,  and  calculations  from  analyses 


CLAY.  51 

of   other  clays,  it  is  doubtful  if   any  could   be  procured  which 
would  be  of  any  advantage  in  the  general  run  of  brick  work. 

"For  the  calculations  in  getting  at  the  value  of  a  fire-clay 
from  its  analysis,  the  formula  used  was  one  given  by  a  German 
chemist,  Dr.  Carl  Bischoff,  who  is  a  recognized  authority  on 
the  subject  of  refractory  materials,  and  whose  investigations  on 
the  subject  have  been  carried  out  and  verified  to  some  extent 
in  this  country.  He  divides  the  clay  into  two  parts,  the  silica 
and  alumina  constituting  the  refractory  part,  and  the  impurities 
the  fluxing  part.  Dr.  Bischoff,  in  this  formula,  uses  the  im- 
purities as  a  whole,  but  in  another  he  divides  them  according 
to  their  relative  strength  as  fluxing  agents. 

"Taking  the  alumina  divided  by  the  total  impurities  as  a 
dividend,  and  the  result  of  the  silica  divided  by  the  alumina  as 
a  divisor,  the  quotient  will  be  a  measure  of  the  refractoriness  of 
the  clay  as  compared  with  that  of  another  clay  treated  in  the 
same  way.  Calling  RO  the  impurities,  the  formula  will  be  as 
follows  : 

ALjO3       SiO2 
RO     ' 


"As  small  a  difference  as  0.05  between  the  quotients  thus 
obtained  for  two  different  clays  indicates  a  difference  in  refrac- 
tory quality  which,  other  things  being  equal,  will  show  itself  in 
a  furnace  test. 

"  These  calculations  are  of  great  use  in  the  comparison  of 
different  clays,  but  the  result  one  might  expect  from  them  may 
be  entirely  changed  when  the  clays  are  made  into  brick.  The 
physical  qualities  of  all  clays  must  be  tested  before  an  abso- 
lutely perfect  comparison  can  be  made.  A  sample  of  the  same 
clay  being  used  by  two  different  brick-makers,  yet  the  one 
brick  made  from  it  may  not  be  as  refractory  as  the  other, 
though  the  sample  may  have  been  thoroughly  mixed  ;  for  if  in 
one  case  the  clay  be  coarsely,  and  in  the  other  finely  ground, 
the  coarse  one  will  stand  a  great  deal  more  heat  than  the  other 
before  it  vitrifies  to  a  homogeneous  mass. 


52  BRICK,  TILES    AND   TERRA-COTTA. 

"  This  has  been  observed  before ;  and  the  writer  has  found  it 
perfectly  true  as  regards  this  clay,  that  the  more  finely  it  is 
ground,  the  less  refractory  it  becomes.  At  the  same  time,  the 
more  finely  it  is  ground,  the  stronger  and  harder  the  brick  be- 
comes, the  more  abrasion  it  will  stand,  and  the  less  likelihood 
there  is  of  its  being  broken  in  handling.  Though  refractoriness 
is  an  essential  of  fire-brick,  yet  it  is  not  the  only  one. 

"  For  the  various  positions  in  which  the  brick  are  placed,  and 
the  duties  they  are  expected  to  perform,  from  the  upper  part  of 
a  blast  furnace,  where  the  heat  is  low,  and  the  abrasion  of  stock 
is  the  greatest  element  in  the  destruction  of  brick,  to  the  ports 
of  an  open-hearth  steel  furnace,  where  intense  heat  is  the  most 
destructive  element,  particular  mixtures  of  clays  should  be 
made  to  get  the  best  results  from  raw  materials. 

"The  greatest  trouble  of  a  brick  manufacturer  is  that  he  can- 
not be  sure  for  what  purpose  the  brick  will  be  used,  or  in  what 
position  in  the  furnace  they  will  be  placed.  Another  trouble 
is  to  find  out  where  the  fault  lies,  when  complaint  is  made. 
This  is  almost  impossible.  It  may  be  in  the  construction  of 
the  furnace,  or  in  bad  bricklaying,  or  the  grade  of  the  brick,  or 
that  the  brick  were  not  hard  burned.  And  if  a  sample  lot  of 
brick  is  sent  to  a  mill  to  be  tested,  the  chances  are  that  when 
the  superintendent  is  asked  how  the  brick  stood  the  test  he  will 
have  forgotten  all  about  them.  The  only  way  for  a  manufac- 
turer to  test  the  brick  is  to  build  a  furnace  and  test  them  him- 
self, and  to  do  this  under,  as  nearly  as  possible,  the  same 
conditions  as  those  under  which  they  will  be  used  in  practice. 

"The  furnace  used  by  the  writer  for  making  such  tests  had 
nearly  the  form  of  a  puddling-furnace.  One-half  of  it  was 
built  of  one  mixture  and  the  other  half  of  another,  running 
through  the  furnace  from  end  to  end.  Bridge-wall,  roof,  side- 
wall  and  neck  would  show  how  the  brick  stood  in  each  posi- 
tion. From  the  results  of  the  tests  a  fair  comparison  could  be 
obtained  of  the  value  of  the  brick.  The  draft  was  a  direct  one 
to  the  foot  of  a  large  chimney,  and  the  coal  used  was  a  mixture 
of  the  best  Cumberland  coal  and  our  own.  A  brick  of  the 


CLAY.  53 

mixtures  used  in  building  the  furnace  was  taken  as  a  standard. 
One  of  these  brick,  with  another,  either  of  some  other  mixture, 
or  some  brick  which  we  wished  to  test,  were  placed  side  by 
side  in  the  neck  of  the  furnace,  which  was  then  fired  as  hard  as 
possible  for  a  certain  length  of  time.  When  the  furnace  had 
cooled  off  the  brick  were  removed,  and  the  effect  carefully 
noted,  particularly  as  regards  shrinkage  and  vitrification,  and 
the  effect  of  the  heat  on  the  furnace  was  also  noticed.  The 
heat  in  36  hours  was  intense  enough  to  vitrify  any  brick,  but 
not  enough  to  destroy  them. 

"As  the  demand  now  is  for  a  hard-burned  brick,  the  diffi- 
culty of  spotted  brick  arises.  These  are  brick  which  appear  to 
be  of  poor  quality,  for  though  a  clay  may  not  contain  more 
than  i  per  cent,  of  oxide  of  iron,  yet  if  it  is  exposed  to  great 
heat  these  spots  will  show ;  and  at  present,  buyers,  with  the 
exception  of  a  few  who  have  learned  their  value,  will  not  take 
spotted  brick.  All  the  brick  from  the  other  places,  which  the 
writer  has  tested,  will,  when  exposed  to  our  greatest  heat,  show 
some  spots,  although  as  they  come  out  of  an  ordinary  kiln 
they  are  free  from  spots. 

"The  two  peculiarities  which  have  made  the  Mount  Savage 
fire-clay  so  famous  are  its  freedom  from  impurities  and  the  fact 
that  this  clay  contains  such  a  proportion  of  silica  to  the  alum- 
ina that  the  brick,  after  they  have  been  hard  burned,  will  swell 
a  little  instead  of  shrinking,  no  matter  how  much  they  are 
heated." 

IMPORTANT    PROPERTIES    OF    FIRE-CLAYS. 

The  compositions  of  fire-clays  differ  very  materially,  as  is 
shown  by  the  results  of  the  various  analyses  which  have  been 
previously  given. 

The  refractory  power  of  all  fire-clay  wares  is  greatly  en- 
hanced at  very  high  temperatures  by  the  presence  of  a  large 
per  cent,  of  alumina. 

Chemists  tell  us  that  fire-clays  will  melt  the  more  readily  in 
very  high  heats  in  proportion  to  the  per  cent,  of  combined  silica 
which  they  contain ;  but  that  clean,  free  silica,  /.  e.y  in  crystals, 


54  BRICK,  TILES    AND   TERRA-COTTA. 

mechanically  combined,  will  not  melt  in  our  melting  heats,  un- 
less fluxed.  Consequently,  they  say,  a  high  proportion  of  free 
silica,  in  the  absence  of  a  high  per  cent,  of  the  fluxes,  lime, 
magnesia,  alkali  and  iron,  is  not  nearly  so  injurious  as  when 
the  silica  is  chemically  combined. 

Every  fire-brick  manufacturer,  who  has  ever  given  the  sub- 
ject of  combined  and  free  silica  attention,  and  who  has  made 
furnace  tests  of  brick  containing  an  excess  of  free  silica,  in  com- 
petition with  brick  carrying  an  excess  of  combined  silica,  by 
placing  such  brick  side  by  side  in  a  furnace,  knows  that  fire- 
brick are  more  refractory  in  proportion  as  the  free  silica  is  re- 
placed by  combined  silica. 

Free  silica  alone  is,  of  course,  infusible,  but  when  it  enters 
into  combination  with  the  other  bodies  commonly  present  in 
fire-clays,  such  clays  become  the  more  easily  fused  the  larger 
the  proportion  of  free  silica  present. 

This  raises  a  very  important  question,  viz. :  Whether  it  is 
not  really  essential  that  there  should  be  made  two  analyses  of 
the  silica  contained  in  any  fire-clay ;  one  analysis  to  determine 
the  per  cent,  of  free  silica,  and  the  other  to  determine  the  per 
cent,  of  combined  silica  which  the  clay  carries. 

The  hydrated  silicates  of  alumina  used  in  fire-brick  manufac- 
ture contain  as  a  rule  from  50  to  65  per  cent,  of  silica,  30  to  75 
per  cent,  of  alumina,  and  1 1  to  15  per  cent,  of  water.  The  re- 
lation between  the  silica  and  the  alumina  is  exceedingly  vari- 
able, owing  to  the  fact  that  a  part  of  the  silica,  which  is  not 
always  the  same,  is  combined,  and  a  part  uncombined ;  hence 
the  necessity  of  the  dual  analysis  of  the  silica  just  mentioned. 
The  quantity  of  water  is  also  variable,  as  part  of  it  is  hygro- 
scopic and  can  be  driven  off  without  injury  to  the  clay.  The 
plasticity  generally  depends  on  the  water  of  combination,  which, 
when  driven  off  at  a  red  heat,  cannot  be  made  to  combine 
again,  so  that  this  property  is  then  entirely  lost.  It  contains, 
beside,  a  small  quantity  of  other  elements,  such  as  potash,  soda, 
lime,  magnesia  and  iron,  and  is  generally  less  refractory  the 
more  it  contains  of  them.  When  it  contains  from  6  to  10  per 


CLAY. 


55 


cent,  it  will  generally  melt.  When  the  clay  is  silicious,  3  to  4 
per  cent,  of  other  substances  make  it  fusible.  When  it  is  alu- 
minous, 6  to  7  per  cent,  of  oxide  of  iron  does  not  make  it  lose 
its  refractory  qualities,  owing  to  the  very  refractory  nature  of 
most  aluminates.  When,  therefore,  the  corrosive  effects  of 
basic  slags  are  to  be  feared,  aluminous  clays  must  be  used. 

.  Almost  all  clays  contain  organic  matter.  The  presence  of 
organic  matter  in  fire-clays  is,  however,  unimportant,  as  it  is 
consumed  or  removed  when  the  brick  are  passed  through  the 
kiln,  as  would  be  the  case  with  an  admixture  of  coal  free  from 
ash. 

Pure  material,  composed  exclusively  of  silica  and  alumina, 
would  be  completely  infusible.  Such  material  is,  however,  ex- 
ceedingly rare.  The  property  of  infusibility  is  always  more  or 
less  compromised  by  the  presence  of  foreign  substances,  which 
tend  to  reduce  it  or  take  it  away  altogether.  The  clay  which, 
according  to  Brogniard,  is  the  most  refractory  when  deprived 
of  its  hygrometric  water,  has  the  following  composition :  Silica, 
57.42  ;  alumina,  42.58. 

While  the  refractory  nature  of  tjie  clay  is  due,  to  a  very 
great  extent,  to  its  chemical  composition,  it  is  not  due  to  it 
alone.  There  are,  probably,  no  two  beds  of  clay  in  the  world, 
or  even  different  parts  of  the  same  bed,  that  have  exactly  the 
same  composition,  and  yet  they  may  be  very  nearly  of  the  same 
quality.  The  power  to  resist  heat  is,  undoubtedly,  owing  to 
the  molecular  condition  of  the  particles,  a  subject  which  has 
been  but  little  studied  and  is  but  little  understood.  Many 
clays,  which  would  be  rejected  from  chemical  analysis  alone, 
are  sometimes  found  in  practice  to  be  excellent  refractory  ma- 
terials. It  has  been  found  that  the  refractory  nature  of  the 
clay  depends  also  to  a  great  extent  on  the  mechanical  arrange- 
ment of  the  particles,  for  of  two  materials  having  exactly  the 
same  chemical  composition,  one  being  coarse  and  the  other 
fine,  the  coarse  may  be  practically  infusible,  while  the  fine  may 
be  more  or  less  easily  fusible.  The  more  porous  the  same  sub- 
stance is,  the  more  infusible  it  will  be.  It  may  be  said  in  gen- 


56  BRICK,  TILES   AND   TERRA-COTTA. 

eral  terms  that  the  value  of  a  given  refractory  clay  will  be 
inversely  as  its  coarseness,  and  as  the  amount  of  iron  contained. 
When  the  amount  of  iron  reaches  5  per  cent.,  the  material,  as 
a  rule,  becomes  worthless.  This  is  true,  however,  only  in  gen- 
eral, for  Pettigand  cites  an  excellent  clay  from  Spain  in  which 
there  is  25  per  cent,  of  iron.  This  is,  however,  an  exception. 
On  this  point  a  recent  writer  says :  "  I  have  before  me  the 
results  of  two  analyses  of  clays  just  brought  up  from  the  labor- 
atory. These  clays  are  very  different  in  composition,  and 
samples  are  sent  five  times  each  month  for  both  analysis  and 
physical  demonstration.  The  mines  are  both  old  ones,  and 
each  concern,  representing  two  of  the  largest  rival  concerns  in 
the  United  States,  has  been  in  business  a  great  many  years, 
but  notice  the  contrast : 

No.  i.  No.  2. 

Silica   49-44  5°-5° 

Alumina 34.26  24.00 

Iron  oxide 7-74  none 

Carbonate  of  lime 1.48  2.70 

Carbonate  magnesia 1 .10  none 

Chloride  of  the  alkalies none  1 .80 

Organic  matter none  i  .01 

Moisture,  etc 5.98  19.99 


Total    100.00       100.00 

"  These  two  clays  are  in  great  demand,  and  are  very  popu- 
lar, for  precisely  the  same  purposes,  with  those  who  use  them." 

In  connection  with  these  analyses  attention  is  invited  to  the 
proportion  of  alumina  and  iron  contained  in  the  two  clays.  It 
is  safe  to  say  that  the  greater  the  proportion  of  alumina  which 
a  clay  contains,  the  less  such  a  clay  is  affected  by  the  presence 
of  a  large  per  cent,  of  iron,  and  this  applies  to  almost  as  great 
an  extent  with  reference  to  alkalies. 

In  order  to  be  useful,  clay  should  be  naturally  plastic  or 
should  artificially  be  made  more  or  less  plastic,  as  this  prop- 
erty is  necessary  to  their  being  moulded  into  the  shapes  re- 
quired. This  plasticity  is  owing,  first,  to  the  fineness  of  the 
particles,  to  the  presence  of  alumina,  and  to  the  water  of  com- 


CLAY.  57 

bination.  It  is  diminished  by  the  presence  of  iron,  lime  and 
magnesia.  The  refractory  nature  of  the  clays,  then,  is  due  to 
the  presence  of  alumina  or  silica  in  excess,  and  to  the  absence 
of  the  fluxes,  potash,  soda,  lime,  magnesia  and  iron. 

The  characteristics  of  all  fire-clays  may  be  said  to  be  that 
they  do  not  effervesce  with  acids,  that  they  make  a  paste  with 
water,  which  is  absorbed  so  rapidly  as  to  make  a  slight  noise. 
This  paste  can  be  drawn  out  without  breaking,  and  is  very 
plastic.  When  dry,  fire-clays  are  solid,  and  break  into  scales 
when  struck.  They  have  a  soapy  feeling,  can  be  scratched  or 
polished  by  the  nail,  can  be  cut  into  long  ribbons  with  a  knife, 
and  appear  somewhat  like  horn.  When  fresh  from  the  quarry, 
fire-clays  have  a  more  or  less  fetid  odor,  owing  to  the  presence 
of  some  partially  decomposed  organic  substances.  In  compo- 
sition they  contain,  as  we  have  seen,  either  silica  or  alumina  in 
excess.  Silica  in  excess  makes  them  rough,  and  takes  away 
most  of  their  plasticity  and  tenacity.  Alumina  makes  them 
very  plastic ;  magnesia  makes  them  very  unctuous,  and  almost 
soapy,  but  does  not  make  them  fusible ;  lime  makes  them  dry 
and  fusible.  Iron  and  other  substances  change  their  color,  and 
beyond  certain  very  restricted  limits  make  them  fusible.  The 
colors,  ranging  from  gray  and  brown  to  black,  are  owing  to  a 
small  percentage  of  bituminous  material.  White  clays  are  gen- 
erally considered  the  best,  but  there  is  no  certainty  about  it,  as 
they  often  crack,  or  even  melt.  It  is  generally  an  excellent 
sign  when  they  leave  unbroken  lines  when  scratched  by  the  nail. 
It  is,  however,  never  safe  to  judge  by  the  eye  or  touch,  as  some 
of  their  chief  characteristics  apply  equally  well  to  materials  not 
in  the  least  refractory,  and  even  those  that  are  peculiar  to  them 
may  be  taken  away  by  improperly  drying  them,  by  careless- 
ness in  storing  or  handling  them,  or  by  allowing  them  to  be- 
come mixed  with  other  substances.  A  preliminary  analysis 
gives  only  a  general  idea  of  their  nature,  but  it  is  not  always  a 
safe  guide  to  the  manufacturer,  who  needs  first  an  analysis  and 
then  an  assay,  for  some  of  the  most  inferior  clays,  if  we  should 
judge  by  their  analyses,  give  excellent  results  when  used  as 


58  BRICK,  TILES    AND   TERRA-COTfA. 

mixtures.  Analysis  is  necessary  both  before  and  after  the 
assay,  but  there  is  a  molecular  force  which  seems  to  exert  a 
greater  influence  in  imparting  a  refractory  value  to  the  material 
than  is  exerted  by  the  chemical  composition.  The  greater  this 
force,  the  less  likely  is  the  heat  to  overcome  it,  either  to  cause 
disintegration  or  chemical  union.  If  possible  to  do  so,  all  clays 
should  undergo  some  process  of  preparation,  with  a  view  of 
purifying  them. 

Every  person  using  clays  should  endeavor  to  get  a  certain 
knowledge  of  their  properties  by  assay.  There  have  been  a 
number  of  these  assays  published,  most  of  which,  though  they 
give  accurate  results,  are  too  complicated  for  ordinary  use. 
The  two  simplest  and  best  are  those  prepared  by  Bischoff 
and  the  foil  assay. 

Bischoff's  assay  is  based  on  the  comparison  of  every  clay 
with  one  from  Garnkirk,  in  Scotland,  which  is  taken  as  a  type. 
For  this  purpose,  the  clay  to  be  examined  is  mixed  with  one, 
two,  three  to  ten  parts  of  quartz,  as  the  case  may  be.  It  is 
then  raised  to  a  known  temperature  and  compared  with  a  piece 
of  the  type  clay  of  the  same  size  and  shape,  which  has  been 
submitted  to  the  same  temperature.  If  the  clay  with  three 
parts  silica  acts  like  the  Scotch  clay  with  one  it  is  called 
three,  and  so  on.  The  best  and  simplest  assay  seems  to  be  the 
one  made  by  the  blow-pipe,  which  consists  in  mixing  a  small 
quantity  of  clay  with  water,  and  then  spreading  it  out  carefully 
on  a  piece  of  platinum-foil  in  a  very  thin  sheet,  which,  when 
completely  dried,  is  submitted  to  the  flame  and  compared  with 
clay  of  known  fusibility  and  prepared  in  the  same  way. 

For  many  purposes  the  density  of  a  clay  is  an  important  ele- 
ment of  consideration.  When  strong  fire-brick  are  needed,  or 
glass-house  pots,  a  dense,  solid  clay  is  desirable.  One  of  the 
superior  qualities  of  the  celebrated  Stourbridge  clay  of  Eng- 
land, and  that  from  Coblentz,  Germany,  as  also  the  Missouri 
clays,  is  their  comparatively  great  density.  That  of  the  first 
named  is  2.435  to  2-553  5  that  of  the  Coblentz,  2.229  to  2.266; 
that  of  the  Cheltenham  clay,  Missouri,  1.708  to  1.715  ;  that  of 
the  Evans  mine,  Missouri,  1.759  to  1.789. 


CLAY.  59 

The  specific  gravity  of  the  clays  examined  by  the  State 
Geologist  of  New  Jersey  was  determined  as  follows : — 

A  prism  about  an  inch  in  length  was  cut  off  the  solid  mass. 
This  was  covered  by  a  film  of  paraffine  and  weighed,  first  in  air, 
then  in  water. 

A  few  were  taken  in  this  way ;  afterward  the  prisms  were 
placed  in  water,  in  a  glass  vial  very  little  larger  than  the  clay, 
and  then  weighed.  No  water  was  absorbed  by  the  clay  in  this 
modification  of  the  method. 

By  this  method  the  openness  or  porous  condition,  which  af- 
fects the  density,  was  taken  into  account.  The  ordinary 
method  neglects  this  condition,  and  the  specific  gravity  as  ob- 
tained is  that  of  the  clay,  sand,  etc.,  or  solid  mass,  without  any 
reference  to  the  spaces  or  interstices  between  the  particles  of 
solid  matter. 

BOND    CLAY. 

The  problem  of  making  a  refractory  brick  from  native  clays 
is  based  upon  the  fact  that  "the  purer  the  clay  the  more  in- 
fusible." Our  purest  clays  are  flint-clays,  which  are  probably 
refractory  by  reason  of  their  structure  as  well  as  their  compo- 
sition. These  then  make  an  admirable  basis  for  the  brick.  As 
they  are  non-plastic,  their  successful  use  compels  the  addition 
of  a  small  amount  of  plastic  clay,  and  on  the  choice  of  this  clay 
all  depends.  A  fine-grained,  sandy  clay,  hard  in  its  native 
state,  and  plastic  when  ground  up  in  water,  makes  the  best 
bond ;  it  is  needless  to  add  it  should  be  pure.  The  more 
aluminous  a  clay  is,  the  more  will  it  shrink  on  burning,  and  if 
the  clay  which  has  been  used  to  incorporate  the  non-plastic 
part  should  shrink  materially  on  burning,  it  would  loosen  the 
bond  between  the  pieces  of  hard  clay  and  make  the  whole 
fabric  unsound.  Therefore,  the  clay  fit  for  a  bond  is  one  in 
which  the  natural  shrinkage  is  at  a  minimum ;  this  condition  is 
found  in  a  fine-grained,  sandy  clay.  It  is  ignorance  of  this 
point,  which  seems  so  simple,  that  has  caused  the  failure  of  so 
many  patent  mixtures  for  refractory  materials.  It  has  seemed 


60  BRICK,  TILES    AND   TERRA-COTTA. 

to  each  man  in  succession  who  has  approached  the  subject, 
that  as  pure  kaolin  is  infusible,  and  pure  sand  is  infusible,  and 
as  these  bodies  represent  respectively  our  ideal  of  plasticity  and 
non-shrinking  qualities,  a  proper  mixture  of  the  two  should 
produce  the  most  desirable  results.  But,  when  such  a  mixture 
is  heated,  the  enormous  shrinkage  of  the  kaolin  loosens  the 
bond  of  the  whole  body  and  makes  it  weak  and  fragile. 

If,  then,  a  pure,  sandy  and  plastic  clay  can  be  found,  the 
bond  is  one  likely  to  be  satisfactory ;  but  the  main  trouble  is  in 
a  lack  of  purity,  for  if  a  clay  fills  the  other  conditions  required, 
it  is  liable  to  be  impure  like  a  stoneware  clay. 

Sufficient  attention  has  not  been  given  by  fire-brick  manu- 
facturers generally  to  the  structure  of  the  fire-brick  as  it  relates 
to  the  size  and  distribution  of  particles  of  flint-clay,  which  forms 
the  base  of  first-class  brick,  and  to  the  bond  clay  that  cements 
the  particles  together.  Before  it  can  be  determined  what  is 
required,  it  must  first  be  ascertained  how  or  why  a  brick  fails 
or  wears  away  in  the  furnace.  A  practical  manager  in  one  of 
the  largest  steel  works  using  the  Siemens  furnaces,  and  who 
has  given  close  attention  and  much  study  to  this  subject,  says, 
that  where  the  particles  or  small  pebbles  of  flint-clay  in  the 
brick  are  of  good  quality  they  do  not  fuse  or  melt,  and  that  it 
is  the  bond  that  holds  the  thicker  particles  that  runs — the 
coarse  particles  floating  away  on  the  fluid  bond-clay.  He  also 
says  that  large  particles  should  not,  for  this  reason,  be  in  the 
brick,  and  the  flint-clay  should  be  prepared  or  screened  so  as 
to  represent  in  size  ordinary  bird-shot,  nothing  larger,  and  it 
should  be  as  free  from  dust  as  possible,  using  as  little  bond- 
clay  as  is  necesrary  to  make  a  sound  brick.  When  the  clay  is 
so  prepared  another  fault  arises,  which  is  this :  The  object  of 
the  wet-pan  is  not  to  grind  what  is  already  sufficiently  fine,  but 
only  to  mix  and  toughen  the  clayey  mass  so  that  when  the. 
clay  is  sufficiently  mixed  it  should  be  immediately  taken  out  of 
the  pan ;  otherwise,  by  longer  grinding,  these  particles  are 
rendered  too  fine,  as  the  extra  grinding,  in  place  of  improving 
the  quality  of  the  mixture,  depreciates  it.  To  achieve  this 


CLAY.  6 1 

equality  in  the  size  of  the  grains  of  the  clay  an  improvement 
might  be  made  in  the  way  the  material  is  screened.  Perforated 
sheet-iron  screens  are  almost  in  general  use,  over  which  the 
clay  as  it  comes  from  the  dry-pan  slides  over  the  dust,  and  a 
portion  of  the  small  pebbles  go  through  the  screens.  On  put- 
ting your  hand  into  the  chute  which  conveys  the  screenings 
back  to  the  dry-pan,  you  will  find  that  if  passed  through  a 
hand-screen  one-half  of  the  material  ought  to  have  been  passed 
to  the  bin,  being  already  sufficiently  fine.  To  obviate  this  ob- 
jection there  should  be  used  a  circular  revolving  screen,  twelve 
wires  to  the  inch,  fixed  slightly  lower  at  one  end  than  the 
other,  so  that,  as  the  clay  is  delivered  into-  the  higher  end,  the 
revolving  screen  will  throw  it  from  side  to  side,  entirely  remov- 
ing every  particle  of  the  required  size,  the  rough  screenings 
falling  out  at  the  lower  end. 

DIGGING,  MINING   AND    MARKETING    FIRE-CLAYS. 

The  extraction  of  the  clays,  feldspar,  kaolins,  fire-sand  and 
other  materials  occurring  in  the  plastic  clay  belt  of  the  State  of 
New  Jersey,  is  mostly  accomplished  by  digging  pits  in  the  beds 
worked,  the  overlying  strata  having  been  previously  removed. 
The  removal  of  the  superficial  beds,  or  "bearing,"  as  it  is  fre- 
quently termed,  and  the  digging,  vary  somewhat  in  the  details 
according  to  the  nature  of  the  circumstances  of  location,  rela- 
tion to  water,  cost  of  labor,  prices  of  materials,  transportation, 
and  business  management. 

The  first  work  on  opening  a  clay  bank,  after  satisfactory  ex- 
ploration, is  to  remove  the  top  dirt  or  bearing.  This  is  done 
in  wagons  in  case  it  has  to  be  carried  to  some  distance,  or  else 
by  cars  on  a  movable  track.  Wheelbarrows  are  occasionally 
used.  At  older  banks,  where  a  large  amount  of  clay  is  dug,  a 
car-track,  or  tramway,  generally  runs  from  the  bank  to  the 
point  of  delivery — main  lines  of  railroads,  or  to  docks  on  navi- 
gable water — and  in  these  the  track  is  generally  laid  quite  to  the 
heading  or  face  of  the  bank,  or  alongside  of  it,  so  that  the  cars 
can  be  easily  loaded.  This  material  is  taken  outside  to  the 


62  BRICK,  TILES   AND   TERRA-COTTA. 

dumping  ground.  Teams  are  in  use  as  the  motive  power,  be- 
ing cheaper  than  steam,  and  quite  as  effective  in  short  distances. 
If  any  of  the  materials  of  this  bearing  are  of  probable  value,  they 
are  sorted  and  put  by  themselves  preparatory  to  future  use,  or 
are  at  once  shipped,  as  desired.  Whenever,  in  working  banks, 
pits,  or  excavations,  areas  have  to  be  filled,  the  top  dirt  is  used 
for  that  purpose. 

According  to  the  general  practice,  the  digging  advances  by 
a  succession  of  contiguous  pits,  and  the  dirt  of  the  pit  which  is 
being  uncovered  is  thrown  at  once  into  that  which  has  just  been 
dug.  In  some  cases  it  is  sufficient  to  use  the  dirt  from  the 
top  of  the  new  pit,  and  the  necessity  of  removal  to  dump  or 
waste  heaps  is  avoided.  But  this  is  exceptional,  as  in  most 
localities  the  amount  of  top  dirt  is  in  excess  of  that  needed  for 
filling,  and  the  surplus  must  be  removed. 

The  cost  of  removing  the  top  dirt  depends  on  so  many  and 
such  constantly  varying  conditions  that  it  is  not  possible  to  give 
prices.  The  nature  of  the  strata,  the  distance  of  removal,  the 
price  of  labor  and  other  items,  enter  into  the  cost. 

Since  the  top  dirt  nearly  everywhere  is  earthy,  the  employ- 
ment of  steam  excavators  or  similar  machinery  is  certainly 
practicable.  The  introduction  of  larger  capital  and  more  com- 
prehensive management  in  the  mining  of  these  clays,  etc.,  will 
be  accompanied  by  more  machinery  to  replace  much  of  the 
slow  and  primitive  methods  now  in  use. 

An  important  question  is  the  location  of  the  heaps  of  top 
dirt  or  dumpings.  This  is  especially  important  at  a  new  local- 
ity, and  care  is  always  necessary  to  avoid  placing  the  dirt  on 
sites  which  are  to  be  worked  at  some  future  time.  By  boring 
or  digging  small  trial  pits,  it  is  easy  to  select  areas  which  are 
not  profitable  for  mining.  Wherever  the  area  worked  over  is 
large,  they  become  the  proper  place  for  storing  them,  if  the 
distance  is  not  too  great. 

The  mining  of  clay  is  generally  done  by  digging  small  pits ; 
these  are  of  different  sizes  according  to  circumstances  of  place 
and  men  to  be  employed.  A  common  size  is  a  rod  square,  or 


CLAY.  63 

an  oblong  pit  of  about  the  same  area.  These  are  dug  through 
the  beds  of  value,  or  as  deep  as  practicable.  Generally  they 
are  made  of  sufficient  depth  to  extract  all  of  a  given  bed  of 
clay,  feldspar,  kaolin,  or  other  material,  which  may  be  worked, 
and  the  digging  or  pitting  stops  at  the  bottom  of  that  bed. 
Thus  in  the  fire-clay  banks,  they  are  dug  through  that  stratum, 
although  in  some  places  where  there  are  valuable  beds  under- 
neath this,  the  digging  is  continued  into  these  lower  beds.  The 
work  is  often  stopped  on  account  of  the  water  in  some  pits ; 
the  danger  of  caving  in,  water  flooding  and  other  such  circum- 
stances, determine  the  depths  of  the  workings. 

It  is  customary  to  have  on  the  ground  at  the  side  of  the  pit  a 
platform  of  a  few  boards,  on  which  the  clay  or  other  material  is 
thrown,  and  if  needed,  the  clay  is  sorted  into  different  grades. 
This  sorting  is  done  piece  by  piece  as  the  spits  are  dug.  A 
gouge  spade  is  used  in  digging  the  clay.  This  differs  from  the 
common  spade  in  having  its  blade  cylindrical,  and  the  upper 
edge  is  broader  than  that  of  the  common  spade,  a  tread  to  re- 
ceive the  weight  of  the  pitman,  neceesary  to  cut  down  into  the 
solid  clay  bed.  The  lump  of  clay,  or  spit,  as  it  is  called,  thus 
loosened  is  taken  by  another  workman,  who  cuts  out  any  nod- 
ules of  pyrites  that  may  be  in  it,  or  any  other  foreign  matter 
which  can  be  removed  by  a  knife,  and  thrown  on  the  platform. 
This  workman  sorts  the  clays  for  ware,  fire-brick,  paper,  alum, 
pipe,  or  other  grades.  The  pitman  confines  his  operations  to 
cutting  down  the  clay,  continuing  this  over  the  pit  area,  and 
then  begins  a  new  spit  level,  and  so  proceeds  till  the  bottom  of 
the  bed  is  reached. 

In  some  of  the  clay  banks  the  working  floor  or  base  is  lower 
than  the  top  of  the  clay  bed,  or  on  a  level  with  the  bottom  of 
the  bank.  The  digging  of  these  banks  is  not  properly  by  pits, 
although  it  goes  forward  by  a  succession  of  pit-like  excavations. 
The  platform  for  the  clay  is  below ;  the  carts  are  driven  to  the 
side  of  the  bank  and  loaded  at  once  by  the  workmen ;  or  the 
clay  is  carted  to  heaps  near  by  and  there  stored,  each  grade  or 
variety  by  itself,  or  it  is  taken  to  boats  or  cars  for  transporta- 
tion to  market. 


64  BRICK,  TILES   AND   TERRA-COTTA. 

Wherever  the  sides  or  the  walls  of  the  pits  or  banks  are  liable 
to  fall  in,  these  have  to  be  strengthened  and  the  workmen  pro- 
tected by  planking  and  bracing.  In  pits  of  ordinary  size,  three 
heavy  planks  on  a  side  are  sufficient,  with  bracing  timbers 
placed  across  between  the  opposite  sides.  Excavation  into  the 
bank  and  above  a  working  level  is  not  often  attended  by  such 
dangers.  The  lateral  thrust  in  pits  appears  to  be  the  more 
common  cause  of  slides  or  caving.  In  sinking  pits  it  is  neces- 
sary and  customary  to  leave  walls  of  clay  I  to  2  feet  thick  on 
the  sides  which  have  been  worked.  These  act  to  hold  up  the 
ground  and  keep  out  the  water.  Most  of  the  danger  from 
slides  comes  from  these  walls,  and  the  pressure  of  wet  drip 
behind  them.  After  the  pit  is  dug  and  before  it  is  filled  up,  a 
part  of  the  clay  walls  is  taken  out  so  that  as  little  as  possible  is 
left  in  the  ground. 

Occasionally  picks  are  used  instead  of  the  gouging  spade, 
when  the  clay  is  very  hard  and  compact.  At  a  very  few  local- 
ities blasting  by  powder  is  employed  to  break  up  extra  hard 
clay  or  strong  layers  associated  with  it.  Undermining  and 
splitting  off  large  masses  of  earth,  clay,  etc.,  by  wedges  or 
powder  are  practiced  at  banks  where  the  materials  are  of  a 
coarser  or  less  valuable  character.  This  is  common  at  the  red 
brick  clay  banks.  It  consists  in  digging  under  at  the  foot  of 
the  bank  as  far  as  can  be  done  with  safety,  and  then  either 
allowing  the  undermined  mass  to  tumble  of  itself,  or  to  force  it 
off  by  using  powder  or  wedges  at  the  top  of  the  bank.  In  this 
manner  hundreds  and  thousands  of  tons  are  tumbled  down  at 
once  and  broken,  making  the  handling  much  easier  than  the 
removal  of  an  equal  weight  by  spading  and  shoveling  down 
from  the  bank. 

As  the  beds  of  clay  are  nearly  always  impervious  to  the  flow 
of  water,  there  is  no  water  to  be  removed,  except  the  very  little 
rain-water  which  falls  or  the  leakage  from  the  surface  drain 
about  the  top  of  the  pits.  This  is  usually  allowed  to  accumu- 
late in  a  deeper  corner  of  the  pit,  and  is  bailed  out  from  time 
to  time  with  a  bucket.  As  the  time  for  sinking  a  pit  of  the 


CLAY.  65 

ordinary  size  does  not  often  exceed  two  or  three  days,  there  is 
little  water  from  these  sources.  The  greatest  amount  of  water 
comes  from  the  sand  or  other  layers  which  are  sometimes  in- 
terstratified  with  the  clay,  and  which  allow  the  water  to  perco- 
late quite  freely  through  .them.  Sometimes  the  clay  bed  is 
found  to  be  quite  sandy  in  the  middle  and  to  allow  water  to 
leak  through. 

At  most  of  the  clay  banks  the  bed  of  clay  is  underlaid  by 
sand,  kaolin,  or  sandy  clay,  and  these  strata  are  generally  full 
of  water,  so  that  the  bottom  of  the  pits  is  wet,  and  the  pits  soon 
fill  with  water  if  it  is  not  pumped  out  or  they  are  not  filled  at 
once  with  earth.  In  banks  where  all  the  clay  bed  is  above  the 
working  floor,  open  ditches  or  partially  covered  drains  are  con- 
structed so  that  the  water  can  run  off  without  further  inconveni- 
ence or  cost. 

In  pits  the  water  has  to  be  hoisted  to  the  level  of  the  work- 
ing floor,  and  thence  carried  off"  by  drains.  Various  modes  of 
raising  water  are  in  use ;  the  most  common  is  by  a  pump 
worked  by  hand  at  intervals,  as  it  is  necessary  to  keep  the  pit 
clear  and  in  working  condition. 

Hoisting  by  buckets  and  a  windlass  has  been  used  in  a  few 
localities.  Steam  power  has  also  been  employed  in  some  places, 
where  the  depth  of  the  pits  and  the  surrounding  wet  ground,  as 
in  tide-meadows,  furnished  a  large  quantity  of  water  to  be 
raised.  The  judicious  arrangement  of  the  location  and  appli- 
ances so  as  to  avoid  heavy  expenses  in  keeping  water  from  the 
pits,  has  much  to  do  with  the  profits  of  clay  digging.  Com- 
prehensive plans  and  skillful  management  are  as  important  in 
this  as  in  any  other  department  of  industry.  The  profits  of 
clay  digging  have  in  some  instances  been  very  large,  but  for 
lack  of  judicious  plans  they  have  not  been  long  continued. 

At  a  few  places  in  New  Jersey  the  extraction  of  the  clay  has 
been  by  underground  work  or  mining.  This  consists,  on  side- 
hills,  in  cutting  short  drifts,  or  tunnels,  in  the  clay  bed,  timber- 
ing them  so  as  to  hold  up,  temporarily,  the  superincumbent 
earth,  and  when  the  work  is  done,  allowing  it  to  fall  in.  By  a 
5 


66  BRICK,  TILES   AND   TERRA-COTTA. 

series  of   drifts  side  by  side  most  of    the  bed    is  in  this  way 
worked  out. 

There  is  some  loss  of  material  in  the  clay  which  has  to  be 
left  at  the  bottom  as  a  floor,  and  at  the  top  as  a  roof  to  hold  up 
the  overlying  sand  or  other  loose  material,  and  to  keep  out  the 
water.  These  drifts  are  inclined  a  little,  if  the  bed  allows  any 
inclination,  to  let  any  water  which  may  get  in  them  by  accident 
run  out.  They  are  narrow,  being  only  wide  enough  for  the 
passage  of  men  with  their  barrows  or  carts.  The  timbering 
consists  of  upright  posts  set  at  the  sides,  at  varying  distances 
apart,  sometimes  close  together,  and  at  others  a  foot  and  a  half 
or  two  feet  apart.  Upon  these,  cross-beams  or  sleepers  are 
laid  to  support  the  roof.  These  drifts  are  seldom  more  than 
100  feet  long.  Wherever  the  beds  of  clay  are  uniformly  thick, 
the  bearing  heavy,  and  the  clays  of  superior  quality  and  value, 
it  may  be  practicable  and  more  economical  than  the  ordinary 
mode  of  stripping  off  the  top  and  pitting  the  clay.  It  is  costly 
and  attended  with  risks ;  and  these  objections  must  be  consid- 
ered in  its  application  to  any  locality.  It  is  believed  that  the 
scarcity  of  clay  at  easily  accessible  depths  for  open  working  will 
in  the  future  compel  the  attention  of  clay-miners  to  it  as  prac- 
ticable, and  the  only  way  in  which  some  of  the  New  Jersey  clay 
territory  can  ever  be  made  available  and  productive. 

The  digging  of  fire- sand ',  kaolin,  and  feldspar  is  carried  on 
very  much  like  that  of  the  clays.  As  the  strata  are  not  imper- 
vious to  water  the  pits  are  generally  smaller,  so  that  the  length 
of  time  in  sinking  one  is  seldom  more  than  a  day.  The  quan- 
tity of  water  to  be  raised  is  commonly  much  greater,  and  in 
some  cases  it  is  so  large  that  it  is  scarcely  possible  or  practi- 
cable to  get  to  the  bottom.  In  working  the  strata  of  these  ma- 
terials there  is  more  loss  than  in  digging  clay.  More  of  the 
bed  is  left  in  the  ground.  In  digging  these  the  gouge  spade  is 
rarely  used,  but  ordinary  shovels  and  spades,  aided  occasion- 
ally by  picks  where  the  material  may  be  more  firm  or  too  hard 
for  spading.  The  loading  is  generally  direct  from  the  pit  or 
the  side  platform  into  carts  or  cars,  and  there  are  fewer  grades, 
rarely  more  than  number  one  and  number  two. 


CLAY.  67 

Nearly  all  of  the  clays,  and  all  of  the  feldspar,  kaolin,  and 
fire-sand,  are  sent  into  market  in  a  crude  state.  They  are 
shipped  in  bulk,  either  in  boats  or  cars.  With  some  varieties, 
as  the  paper  and  ware  clays,  more  care  is  taken  in  keeping 
them  clean  and  free  from  admixture  with  inferior  grades. 
Formerly  the  paper-clays  were  shipped  in  barrels,  but  at  the 
present  time  they  are  generally  transported  in  bulk. 

The  mines  from  which  fire-clays  are  taken  should  be  kept  in 
first-class  condition,  so  as  to  be  able  to  meet  all  demands  made 
upon  them  for  raw  material,  and  nothing  but  pure  clean  ma- 
terials should  be  sent  to  the  factory  to  be  made  into  fire-brick. 

In  mining  fire-clay  more  care  is  required  than  in  mining  iron 
ores,  or  even  coal.  It  is  considered  good  ore  that  produces  fifty 
per  cent,  metallic  iron ;  the  other  half  consists  of  foreign  in- 
gredients that  are  run  off  from  the  furnace  as  slag.  An  acci- 
dental or  careless  increase  of  this  foreign  matter  results  in  no 
more  serious  consequences  than  the  lessening  of  the  percentage 
of  metallic  iron  produced,  thus  causing  a  slight  increase  in  the 
cost  of  the  pig-iron.  The  case  is  very  different  with  fire-clay. 
Foreign  matter  carelessly  mixed  in  with  fire-clay  may  easily 
spoil  a  large  quantity  of  brick.  Fire  clay  often  runs  in  veins 
contiguous  to  iron  ore  or  limestone,  or  even  closely  associated 
with  them,  and  it  takes  but  little  of  either  of  them  to  ruin  a 
large  quantity  of  clay.  The  writer  remembers  a  case  in  point 
where  a  part  of  the  clay  supply  came  from  a  mine  where  the 
clay  bed  was  directly  under  the  limestone.  The  latter  was  first 
got  out,  going  to  the  furnace  for  flux ;  afterward  the  fire-clay 
was  taken  out.  Some  slight  changes  among  the  hands  em- 
ployed at  the  mines  resulted  in  a  quantity  of  the  small  lime- 
stone chippings  getting  mixed  with  the  fire-clay.  As  they 
were  both  the  same  color,  it  passed  unnoticed  until  some 
thousands  of  brick  were  spoiled. 

In  many  fire-clay  mines  streaks  or  spots  come  in  at  irregular 
intervals,  confined  to  no  particular  line  in  the  vein,  of  foreign 
matter  very  injurious  to  the  clay,  or  sometimes  clay  strongly 
impregnated  with  calcareous  or  ferruginous  matter,  that  need 


68  BRICK,  TILES    AND   TERRA-COTTA. 

great  care  in  order  to  separate  them ;  hence  none  but  experi- 
enced men  should  be  employed  for  the  work,  men  who  by  long 
practice  can  tell  good  clay  from  bad  as  if  by  second  nature. 

The  Glenboig  Union  Fire  Clay  Company,  Limited,  of  Glas- 
gow, Scotland,  mines  its  fire-clay  near  Glenboig.  On  making 
the  descent  of  the  shaft,  the  total  depth  of  which  is  about  seven- 
teen fathoms,  while  in  transverse  section  it  measures  13  by  4^ 
feet,  we  find  the  clay  at  the  working  face  to  be  of  a  very  hard 
texture,  and  requiring  to  be  blasted.  The  method  of  working 
is  that  which  is  called  in  Scotland  the  "  stoop-and-room " 
system — Anglice,  "  pillar-and-stall."  Some  of  the  pillars  or 
stoops  are  30  feet  square ;  others  are  60  feet,  and  those  im- 
mediately around  the  bottom  of  the  shaft  are  about  70  feet 
square.  There  is  an  excellent  roof  to  the  workings — generally 
about  three  feet  of  rough,  hard  sandstone.  The  pumping  is  ef- 
fected by  means  of  a  double  action  steam-pump.  It  has  a  con- 
tinuous water  discharge,  which  is  delivered  by  means  of  a  four- 
inch  pipe  to  a  tank  situated  at  the  back  of  the  works,  and  at 
such  an  elevation  that  the  water  can  flow  by  gravitation  to  the 
steam  boilers,  condenser,  etc.  The  pit  is  worked  by  a  hori- 
zontal fourteen-inch  cylinder  high-pressure  engine,  and  winding 
gear  embodying  all  the  latest  improvements. 

The  fire-clay,  which  is  got  in  irregular  masses,  frequently 
weighing  one  or  two-hundred  weight  or  more,  is  raised  to  a 
height  of  about  35  feet  above  the  pit  mouth,  and  run  out  on  a 
tramway  either  to  a  clay  "  bing  "  or  direct  to  the  crushing  mill. 
When  the  clay  is  exposed  to  the  weather  for  some  time,  it  be- 
comes physically  disintegrated  to  such  an  extent  that  the  sub- 
sequent crushing  operation  is  very  easily  effected.  By  weather- 
ing, the  clay  is  also  rendered  much  more  suitable  for  the  pro- 
duction of  such  goods  as  require  a  fine  surface  texture. 

The  following  tables  of  analyses  made  in  the  laboratory  of 
the  Geological  Survey  of  New  Jersey,  are  here  presented  as  a 
convenient  arrangement  of  facts  for  reference.  In  the  first  col- 
umn the  silica  which  is  in  combination  is  given ;  in  the  sec- 
ond, the  alumina ;  in  the  third,  the  water  of  combination ;  in 


CLAY.  69 

the  fourth,  the  sum  of  these  three  constituents,  or  the  essential 
elements  of  a  clay ;  in  the  fifth  and  sixth,  the  titanic  acid  and 
quartz  sand  appear ;  in  the  seventh,  the  sum  of  these  two ;  in 
the  eight,  ninth,  tenth,  eleventh,  and  twelfth  are  given  the  pot- 
ash, soda,  lime,  magnesia,  and  sesquioxide  of  iron ;  the  thir- 
teenth gives  the  sum  of  these ;  the  fourteenth  has  the  hygro- 
scopic water  (moisture),  fluxing  agents.  In  the  last  column 
the  total  of  the  constituents  determined  is  placed. 


70 


BRICK,  TILES   AND   TERRA-COTTA. 


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Sand  Hills  

Charles  A.  Campbell  &  Co., 
Sand  Hills.  White  fire-cla 
Freeman  &  Vanderhoven, 

E.  F.  Roberts, 
Pits  near  Eagleswood  
E.  F.  &  J.  M.  Roberts, 
Near  South  Amboy  
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(Selected)  
George  Such, 
Burt's  Creek,  washed  clay. 
Say  re  &  Fisher, 
Sayreville  

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BRICK.  TILES   AND   TERRA-COTTA. 


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CLAY.  77 

The  tables  of  analyses  above  given  are  valuable  as  a  basis  for 
comparisons  and  for  further  examinations  and  practical  tests. 
The  analyses  were  all  made  by  the  same  chemist  and  under  like 
conditions.  At  present  it  does  not  appear  to  be  possible  to 
estimate  accurately  or  even  approximately,  from  the  results  of 
chemical  analysis,  the  fire-resisting  power  of  all  clays  before 
they  have  been  tested  in  the  fire.  This  is  evident  from  the 
table.  From  some  of  these  analyses  we  should  anticipate  fus- 
ion of  those  clays,  yet  they  are  noted  fire-clays.  Analyses 
need  to  be  supplemented  by  fire-tests,  and  these  should  be 
of  the  specimens  examined.  A  couple  of  preliminary  fire-tests 
have  been  made  with  the  specimens  represented  in  the  above 
table  and  some  others.  They  were  incomplete,  and  in  the  case 
of  many  specimens  indecisive.  Want  of  time  since  the  recep- 
tion of  many  of  these,  and  since  the  analyses  were  finished, 
prevented  the  completion  of  this  most  interesting  and  promis- 
ing series  of  investigations.  The  first  trials  were  made  in  a 
crucible  steel  furnace,  at  the  Newark  Steel  Works.  The  clays 
were  cut  in  the  form  of  tetrahedrons,  seven-eighths  of  an  inch 
on  a  side.  The  clays  as  they  came  ¥rom  the  pits  and  mines, 
well-dried  at  summer  temperatures,  were  used  in  all  cases 
where  they  could  be  cut  easily  and  with  regularity.  The  hard 
clays,  as  those  from  coal  formations,  were  pulverized  and 
moulded  into  the  desired  shape.  All  were  put  in  a  graphite 
crucible,  and  set  in  a  steel  furnace,  and  exposed  for  one  heat 
(about  four  hours),  at  least  up  to  the  melting  point  of  ham- 
mered steel.  Among  the  specimens  thus  tested  there  were 
several  pipe,  saggar,  stone  ware,  yellow  ware,  and  alum  clays. 
These  were  all  more  or  less  fused.  Some  of  them  melted  down 
to  flattened  buttons  ;  others  were  rounded  considerably.  Some 
fire-clays  were  partially  fused,  others  were  sharp  and  true,  as  at 
the  outset.  As  far  as  it  is  possible  to  generalize,  the  clays  con- 
taining much  oxide  of  iron  and  potash  together,  were  fused. 
The  iron,  when  it  exceeds  2.5  per  cent.,  appears  to  be  more 
detrimental  than  the  potash.  Nearly  all  of  the  more  sandy 
clays  were  slightly  fused.  The  rich  fire-clays  of  Wood- 


78  BRICK,  TILES    AND    TERRA-COTTA. 

bridge,  the  Raritan  river  banks  and  South  Amboy  remained 
unaffected — not  even  glazed.  The  Missouri  and  the  more 
noted  British,  French  and  Belgian  clays  also  stood  well. 

METHOD   OF   ANALYSIS    FOR    FIRE-CLAYS,    FELDSPARS,   KAOLIN,  AND 
FIRE-SANDS. 

The  method  of  chemical  analysis  adopted  and  pursued  in  the 
examinations  of  the  fire-clays,  feldspars,  kaolins,  and  fire-sands, 
which  are  given  on  pages  70-76  was  as  follows  :  One  gramme  of 
the  air-dried  pulverized  material  was  digested  in  sulphuric  and 
hydrofluoric  acids  until  the  silica  was  completely  dissipated ; 
the  residue  was  dissolved  in  hydrochloric  acid  (a  few  drops  of 
nitric  acid  being  added  to  oxidize  the  iron),  and  the  alumina, 
sesquoixide  of  iron  and  titanic  acid  were  precipitated  by  am- 
monia (in  some  cases  by  acetate  of  ammonia).  In  the  filtrate 
the  lime  was  precipitated  by  oxalate  of  ammonia,  and  weighed 
as  carbonate.  The  filtrate  from  the  lime  was  divided  into  two 
equal  portions.  In  one  of  these  the  magnesia  was  determined 
by  precipitation  by  phosphate  of  ammonia.  The  second  por- 
tion was  evaporated  to  dryness  and  heated  to  drive  off  the  am- 
moniacal  salts.  The  residue  was  dissolved  and  chloride  of  barium 
was  added  to  remove  the  sulphuric  acid,  and,  then  caustic  lime 
to  remove  the  magnesia.  The  liquid  was  boiled  and  then  fil- 
tered. To  the  filtrate,  ammonia  and  carbonate  of  ammonia  were 
added  to  remove  the  chloride  of  barium  and  lime ;  the  liquid 
was  filtered,  evaporated  to  dryness,  and  the  ammonia  salts 
driven  off  by  ignition.  The  potash  was  precipitated  by  bichlo- 
ride of  platinum  and  weighed  as  potassio-bichloride  of  plati- 
num. The  alcoholic  filtrate  was  evaporated  to  dryness,  the 
platinum  compound  decomposed  by  heating  to  redness  with 
oxalic  acid ;  treated  with  water ;  filtrated ;  a  few  drops  of  hy- 
drochloric acid  added;  evaporated  to  dryness,  and  weighed  as 
chloride  of  sodium. 

A  second  sample  (one  gramme)  was  treated  with  hydro- 
fluoric and  sulphuric  acids,  as  before,  and  then  ammonia  added 
to  precipitate  titanic  acid,  alumina  and  oxide  of  iron.  This 


CLAY.  79 

precipitate  was  reserved  for  the  determination  of  the  titanic 
acid.  The  filtrate  was  treated  as  before  for  the  determination 
of  the  potash  and  soda,  as  duplicates. 

A  third  sample  was  fused  with  carbonates  of  potash  and 
soda;  the  fused  mass  treated  with  water;  hydrochloric  acid 
added  in  excess  ;  evaporated  to  dryness  to  render  the  silicic  acid 
insoluble ;  treated  with  dilute  hydrochloric  acid ;  heated,  and 
then  filtered  for  the  total  silicic  acid.  This  weighed  determi- 
nation was  checked  by  the  difference  in  the  analysis  by  hydro- 
fluoric acid.  The  alumina,  oxide  of  iron  and  titanium  were 
precipitated  by  ammonia  as  in  the  first  sample.  Lime  and 
magnesia  were  also  determined  as  before  (duplicate  determi- 
nations). 

The  precipitate  in  the  second  sample,  reserved  for  the  titan- 
ium determination,  was  treated  with  a  solution  of  caustic  pot- 
ash and  heated,  to  remove  the  alumina.  The  insoluble  portion, 
consisting  of  oxide  of  iron  and  titanic  acid,  was  collected  on  a 
filter,  burned,  fused  with  bi-sulphate  of  potash,  dissolved  in 
water,  and  saturated  with  hydrosulphuric  acid  gas,  to  reduce 
the  iron  oxide.  The  liquid  was  filtered  and  boiled ;  the  titanic 
acid  was  precipitated  and  collected  on  a  filter,  then  burned  and 
weighed. 

For  the  determination  of  the  quartz  the  clays  were  digested 
in  the  sulphuric  acid,  and  the  liquid  filtered.  The  insoluble 
matter  on  the  filter  was  burned  and  weighed  as  a  duplicate  of 
the  total  silica.  This  insoluble  matter  was  then  boiled  in  a  so- 
lution of  potash,  and  the  undissolved  residue  weighed  as 
quartz.  These  determinations  were  duplicated  by  the  same 
method. 

The  moisture  or  hygroscopic  water  was  determined  by  heat- 
ing over  a  water-bath,  and  the  loss  at  212°  F.  (100°  C.)  taken 
as  its  amount.  The  samples  were  then  heated  to  redness, 
ignited,  and  the  loss  noted  as  combined  water.  In  most  of  the 
dark-colored  clays  there  was  some  organic  matter. 

In  a  few  analyses  this  was  estimated ;  in  others  the  combined 
water  includes  very  small  amounts  of  organic  matter. 


80  BRICK,  TILES    AND   TERRA-COTTA. 

The  iron  was  determined  by  volumetric  analysis,  using  the 
method  by  photo-chloride  of  tin. 

TERRA-COTTA    CLAYS. 

In  the  manufacture  of  terra-cotta  in  England  an  important 
clay  has  long  been  the  potter's  clay  of  North  Devon  and  Dor- 
setshire, the  analysis  of  which,  by  Weston,  is  as  follows:  — 

North-Devon. 

Alumina 29.38 

Silica 52.06 

Lime 0.43 

Magnesia 0.02 

Iron  oxide 2.37 

Potash 2.29 

Soda 2.56 

Water  combined 10.27 

Dorsetshire 

Alumina 32.11 

Silica 48.99 

Lime 0.43 

Magnesia 0.22 

Iron  oxide 2.34 

Potash 2.31 

Soda 2.33 

Water  combined 9.63 

Each  of  these  clays  contains  a  small  amount  of  alkalies.  The 
clays  of  the  coal  measures,  technically  known  as  the  "  fine 
clays,"  are  also  much  esteemed  for  this  purpose. 

In  the  north  of  England  and  in  Scotland,  the  purest  lumps 
of  fire-clay,  selected  by  their  color  and  texture,  are  used  by 
themselves  in  the  production  of  terra-cotta ;  but  the  concerns 
of  Mr.  Blashfield  of  Stamford,  and  Doulton  and  others  near 
London,  produce  a  body  of  much  better  texture  by  a  careful 
and  thorough  mixture  of  clays. 

It  requires  greater  care,  and  is  slightly  more  expensive  for 
labor ;  but  these  are  small  considerations  in  comparison  with 
the  increased  compact,  homogeneous  and  better  vitrified  body 
which  results  from  using  a  mixture  of  clays. 


CLAY.  8 1 

The  precise  combination  of  clays  varies  with  the  appearance 
desired  for  the  terra-cotta ;  sometimes  it  is  a  light  cream,  or  a 
soft  buff  color ;  at  other  times  it  may  be  a  cherry-red,  or  a  hard 
brownish-red  color. 

A  partial  vitrification  of  the  mass  is  desirable  in  the  produc- 
tion of  terra-cotta,  as  it  enhances  the  durabifity  of  the  body ; 
and  in  order  to  achieve  this,  clays  like  the  Dorsetshire  are 
added,  the  small  amount  of  alkalies  which  they  contain  acting 
as  a  flux  and  fusing  the  body  to  a  harder  consistency. 

New  Jersey  produces  a  great  variety  of  clays,  and  the  belt  of 
country  underlaid  by  them  extends  entirely  across  the  State, 
and  as  described  by  the  State  geologist,  includes  an  area  of 
three  hundred  and  twenty  square  miles ;  while  the  area  within 
which  these  deposits  have  been  worked  to  the  present  time  is 
only  about  seventy  square  miles,  the  actual  openings  of  the 
clay  beds  being  only  a  very  small  fraction  of  the  last-named 
area. 

The  average  depth  of  these  clay  deposits  is  more  than  three 
hundred  and  fifty  feet,  and  the  order  of  supersession  is  shown  in 
the  following  table: — 

Feet. 

1.  Dark-colored  clay  (with  beds  and  laminae  of  lignite)   50 

2.  Sandy  clay,  with  sand  in  alternate  layers 40 

3.  Stoneware  clay  bed 30 

4.  Sand  and  sandy  clay  (with  lignite) 50 

5.  South  Amboy  fire-clay  bed 20 

6.  Sandy  clay,  generally  red  or  yellow 3 

7.  Sand  or  kaolin 10 

8.  Feldspar  bed 5 

9.  Micaceous  sand  bed 20 

10.  Laminated  clay  and  sand 30 

11.  Pipe  clay  (top  white)   10 

12.  Sand  clay,  including  leaf  bed 5 

13.  Woodbridge  fire-clay 20 

14.  Fire  sand  clay 15 

{Fire-clay 15 

Sand  clay 4 

Potter's  clay 20 

These  clays  are  one  of  the  most  important  elements  of  the 
material  wealth  possessed  by  the  State. 
6 


82  BRICK,  TILES    AND   TERRA-COTTA. 

Large  quantities  of  clays  are  marketed  annually  for  making 
fire-brick,  pottery,  terra-cotta  ware  of  all  kinds,  tiles,  retorts, 
crucibles,  facings  for  wall-papers,  etc. 

The  average  price  per  ton  is  four  dollars,  and  the  average 
aggregate  production  of  fire-clay  alone,  in  its  crude  state,  ex- 
ceeds one  and  a  half  million  dollars. 

New  uses  for  clay  of  this  character  are  being  developed  all 
the  while.  The  New  York  Terra-cotta  Lumber  Company  has 
established  large  works  at  Perth  Amboy  for  the  manufacture  of 
lumber  by  mixing  resinous  sawdust  with  the  wet  clay,  which 
is  left  porous  after  the  burning,  by  the  sawdust  being  con- 
sumed. 

In  speaking  so  highly  of  the  terra-cotta  clay  of  New  Jersey, 
we  do  not  mean  to  be  understood  that  it  is  suitable  for  use  with- 
out any  mixtures  or  other  special  preparation,  as  no  terra- 
cotta clay  can  be  so  worked  with  safety ;  neither  should  the 
terra-cotta  clay  be  confounded  with  fire-clay,  the  requirements 
for  which  are  different ;  but  that  of  New  Jersey  is  also  one  of 
the  best  in  this  country,  or  in  the  world. 

The  body  of  the  clay  which  has  been  described  is  best  de- 
veloped at  Woodbridge  and  Perth  Amboy,  and  is  practically 
inexhaustible ;  and  although  its  presence  has  been  known  for 
nearly,  if  not  quite,  two  centuries,  its  employment  for  the  pro- 
duction of  architectural  terra-cotta  is  of  but  very  recent  years. 

It  is  conveniently  situated  between  the  large  and  wealthy 
cities  of  New  York  and  Philadelphia,  and  being  contiguous  to 
the  seaboard,  and  in  easy  communication  by  rail  with  all  the 
developing  cities  of  the  country,  this  section  should  become  to 
us  what  the  Staffordshire  district  is  to  England. 

The  color  of  the  rich  New  Jersey  clay,  denuded  of  the  soil 
and  often  exposed,  varies  in  shade  from  a  light  cream-color,  al- 
most white,  to  a  soft  buff,  and  sometimes  the  clay  will  be  of  a 
dark-red  color  owing  to  the  abundant  presence  of  the  oxide  of 
iron,  a  very  light  trace  of  which  impregnates  all  the  clay  in  the 
circumjacent  region. 

The  red  clays  containing  oxide  of  iron  in  abundance  are  used 


CLAY.  83 

only  when  it  is  desired  to  give  the  terra-cotta  a  deep-red  brick 
color,  which  is  sometimes  done  for  friezes,  panels,  tiles,  and 
other  architectural  requirements. 

For  a  long  distance  the  way  between  Woodbridge,  Perth 
Amboy  and  New  Brunswick  is  marked  by  many  hollows  and 
excavations  which  are  sometimes  of  great  depth.  From  the 
bottom  of  these,  winding  wagon  roads  lead  through  banks  of 
clay  in  which  large  gangs  of  laborers  are  regularly  at  work  dig- 
ging material  to  be  used  in  the  production  of  terra-cotta  and 
fire-brick,  and  removing  that  which  is  unsuitable  for  these  pur- 
poses. 

The  surface  of  the  country  is  undulating,  and  is  but  thinly 
settled,  and  often  a  heavy  growth  of  birches,  maples,  and  young 
pines  spreads  over  it,  giving  no  indications  of  the  riches  it  con- 
ceals, for  underlying  it  is  one  vast  bed  of  terra-cotta  clay, 
which  for  fineness  of  texture  and  plasticity  has  no  equal  in  the 
world. 

In  applying  the  term  plasticity  to  this  clay,  we  do  not  mean  it 
in  the  common  acceptance  of  that  term ;  but  in  addition  to  the 
quality  of  receiving  and  giving  form,  that  also  of  retaining  it, 
not  only  while  it  is  being  moulded,  but  in  that  most  trying  time 
to  all  clays,  which  is  the  period  that  it  is  yielding  its  chemical 
water,  "  going  through  the  sweat." 

It  may  not  be  generally  known  that  all  things  made  of 
moulded  clay,  although  they  may  appear  to  be  perfectly  dry 
when  they  go  into  the  kiln,  again  become  softer  and  almost  as 
plastic  as  they  were  when  first  moulded,  and  it  is  this  stage  of 
burning  that  is  so  destructive  to  form  in  the  production  of  ar- 
tistic and  architectural  terra-cotta.  In  describing  this  critical 
period  in  burning,  we  have  used  the  common  parlance  of  the 
laborers  employed  about  kilns,  for  two  reasons,  the  first  being 
that  there  is  no  technical  term  applicable  to  the  same  condition 
of  things,  and  the  second  is  that  "  going  through  the  sweat"  is 
a  most  accurate  and  literal  description.  Should  the  adobes  or 
sun-dried  bricks  of  Egypt,  which  have  been  exposed  to  the  in- 
fluences of  that  moisture-extracting  climate  for  more  than  three 


84  BRICK,  TILES    AND    TERRA-COTTA. 

thousand  years,  be  placed  in  a  kiln  and  burned,  the  result 
would  be  the  same ;  they  would  "  go  through  the  sweat"  and 
become  soft  and  plastic  before  they  were  burned  into  hard 
bricks. 

The  mechanical  water  has  been  extracted  from  them,  but  the 
chemical  water  contained  in  the  clay  has  never  been  driven  out 
by  burning.  The  adobe  before  burning  could  be  soaked  in 
water,  and  in  a  few  hours  it  would  be  just  as  plastic  as  it  was 
when  first  made,  thousand  of  years  ago,  but  after  burning  its 
plasticity  is  forever  lost. 

The  vitrifying  ingredients  usually  added  to  the  terra-cotta 
clays  are  pure  white  sand,  old  pottery,  and  fire-bricks  finely 
pulverized,  and  clay  previously  burned,  termed  "grog;"  these 
are  employed  in  various  proportions,  sometimes  amounting  to 
nearly  thirty  per  cent,  of  the  mass. 

The  alkaline  salts  contained  in  the  clays  yield  an  efflores- 
cence, which  acting  upon  the  silicates  of  the  surface,  vitrify  to 
a  greater  degree  the  exterior  of  the  terra-cotta,  and  this  harder 
face  should  remain  intact,  and  under  no  avoidable  circum- 
stances be  allowed  to  be  chipped,  chiseled,  or  broken. 

Almost  any  clay  that  will  harden  under  the  action  of  fire 
without  cracking,  providing  it  is  free  from  stones,  will  make 
good  common  building  brick ;  but  it  is  not  so  with  the  making 
of  terra-cotta. 

Terra-cotta  being  made  of  hollow  and  larger  forms  than 
common  brick,  demands  a  material  which  has  a  minimum 
shrinkage  in  the  process  of  drying  and  burning.  Where  the 
contraction  is  too  great,  the  liability  to  crack  in  drying  or  to 
fire  check  in  burning,  is  increased  to  such  an  extent  as  often  to 
make  the  cost  exceed  the  value  of  production. 

For  this  reason  the  expert  manufacturer  will  seek  for  such 
clays  orNCombinations  of  clays  as  will  contract  or  shrink  as  lit- 
tle as  possible,  in  reaching  the  condition  of  hardness  and  text- 
ure which  constitutes  good  terra-cotta. 

The  best  standard  texture  and  hardness  for  architectural 
terra-cotta  is  any  good  sandstone — test  with  sharp  steel. 


CLAY.  85 

Terra-cotta  should  be  gritty  in  texture  and  slightly  porous. 
If  it  is  vitreous,  it  will  also  be  brittle.  A  small  confined  piece 
may  sustain  a  great  weight,  but  a  large  exposed  portion  is  li- 
able to  fracture  under  climatic  extremes  when  heavily 
weighted  in  part. 

The  slightly  porous  quality  enables  it  to  absorb  enough 
water  from  the  mortar  in  which  it  is  set  so  as  to  remain  where 
the  mason  places  it.  If  vitreous  instead  of  porous,  it  is  liable 
to  be  slipped  out  of  place  before  the  mortar  has  sufficiently  set 
of  itself  to  hold  it.  It  is  a  safe  rule  to  use  clays  that  will  shrink 
only  one-eighth  in  bulk  during  the  conversion  from  plastic  clay 
to  terra-cotta,  but  this  ratio  of  shrinkage  must  always  be  ac- 
companied by  such  a  tenacity  or  strength  as  will  serve  to  hold 
all  its  particles  together  during  the  process,  so  that  there  may 
be  no  cracks  or  flaws  in  the  final  product. 

KAOLIN  OR  CHINA  CLAY. 

Kaolin  is  the  name  given  by  the  Chinese  to  the  fine  white 
clay  used  in  making  porcelain.  It  is  furnished  by  the  decom- 
position of  granite  and  other  rock,  the,  constituents  of  which  are 
quartz,  mica,  and  feldspar,  the  mouldering  or  decomposition 
being  caused  by  the  joint  action  of  air  and  water. 

A  much  similar  clay,  to  which  the  Chinese  name  has  been 
given,  occurs  near  St.  Anstel,  in  Cornwall,  a  county  in  the 
southwest  of  England. 

The  kaolin  of  Cornwall,  as  well  as  that  near  Limoges,  in 
France,  and  which  latter  clay  was  discovered  in  1 768,  is  pro- 
duced by  the  decomposition  of  pegmatite,  a  granite  in  which 
there  is  very  little  of  mica  or  quartz. 

The  clays  which  are  much  valued  by  porcelain-makers  may 
be  represented  by  the  formula  Al2O3,3SiO3-|-2HO ;  all  clays 
being  silicates  or  hydrated  silicates  of  alumina. 

The  term  kaolin,  when  used  by  practical  potters,  usually 
means  the  finer  and  white  qualities,  or  such  as  will  make  the 
grades  of  ware  known  as  white  granite  or  stone  porcelain — 
called  China  clays.  Such  clays  are  found  in  many  parts  of  the 


86  BRICK,  TILES   AND   TERRA-COTTA. 

United  States,  notably  in  Maryland,  Pennsylvania,  and  Dela- 
ware. The  actual  quantity  is  great,  as  there  are  fifty  to  sev- 
enty-five potteries  in  the  United  States,  which  use  from  100  to 
3000  or  4000  tons  per  annum  each.  The  price  is  governed  by 
color  and  plasticity.  Some  clays  are  highly  valued  for  their 
color  only,  others  for  their  plastic  property.  The  demand  is 
large  and  steady  for  good  China  clays.  To  ascertain  the  value 
of  such  clays  send  a  piece  just  as  it  comes  from  the  earth  to 
any  practical  potter.  Potters  test  these  matters  by  fire  and 
water.  Vessels  coming  from  Liverpool  are  now  bringing  En- 
glish clays  as  ballast,  and  they  are  sold  at  about  the  same 
price  as  American  kaolin.  Flint  or  ground  quartz,  or  feldspar, 
or  ground  feldspathic  rock,  is  largely  used  by  potters,  and  is  in 
good  demand. 


CHAPTER  III. 

MAKING  AND  BURNING  A  KILN  OF  HAND-MADE  BRICK. 

THE  methods  of  manufacturing  building  brick  by  the  hand 
process  greatly  differ  in  various  portions  of  the  United  States, 
and  in  some  parts  of  the  country  the  period  doing  which  their 
manufacture  can  be  conducted  extends  through  the  entire  year, 
as  in  Texas ;  but  in  the  colder  States  of  the  North,  as  in  Maine, 
the  season  averages  only  about  four  and  one-half  months.  A 
great  variety  of  clays  are  necessarily  found  in  a  country  cover- 
ing such  a  wide  expanse  of  territory  as  does  ours.  On  account 
of  the  difference  in  clay  found  in  various  localities,  different 
forms  of  brick  machines,  and  also  different  methods  of  manu- 
facturing by  hand  are  necessary,  and  they  vary  according  to 
the  section  of  the  country ;  but  the  method  which  we  shall  de- 
scribe is  the  one  commonly  employed  in  the  large  Eastern 
States.  The  first  operation  in  the  manufacture  of  brick  by  the 
hand  process  is  the 

PREPARATION  OF  THE  CLAY. 

The  first  step  in  the  preparation  of  the  clay  consists  in  re- 
moving the  vegetable  soil,  which  is  carried  to  the  "  floors," 
which  are  the  level  places  where  the  brick  are  moulded.  The 
soil  is  uniformly  spread  over  the  floors  to  the  depth  of  about 
two  inches,  and  is  allowed  to  remain  from  the  close  of  one 
brick-making  season  till  the  commencement  of  another,  and  is 
then  smoothed  or  "luted"  and  afterwards  rolled  and  again 
"luted."  The  preparation  of  the  clay  is  conducted  either  by 
drying  or  by  wintering.  The  clays  of  Maine  are  commonly 
dried,  and  are  not  dug  and  wintered  or  "  weathered,"  although 
much  of  the  clay  used  in  various  portions  of  New  England 
freezes  during  the  winter,  and  when  such  is  the  case  the  clay  is 

(87) 


88  BRICK,  TILES    AND   TERRA-COTTA. 

used  without  drying;  but  the  experience  of  practical  brick- 
makers  in  the  State  of  Maine  has  demonstrated  that  the  light  clay 
which  has  been  weathered  does  not  work  quite  so  smoothly 
and  easily  as  clay  that  has  been  dried.  Clays,  which  are  of  a 
strong  nature,  make  the  best  brick  when  they  are  exposed  to 
the  weather  until  the  particles  are  disintegrated,  and  this  is  best 
effected  by  the  action  of  frost,  the  water  diffused  through  the 
substance  expanding  by  freezing  and  breaking  it  in  every  direc- 
tion. The  clay  becomes  the  more  effectually  reduced,  and 
therefore  more  readily  tempered  and  moulded,  in  proportion  to 
the  period  for  which  it  is  exposed  to  the  action  of  the  frost.  In 
the  Middle  States  the  brick-making  season  usually  commences 
about  the  middle  of  April,  and  the  first  thing  which  has  to  be 
done,  after  attending  to  the  floors,  repairing  the  sheds  and 
kilns,  is  the 

TEMPERING  OF  THE  CLAY. 

Various  methods  for  tempering  clay  are  in  use  in  different 
parts  of  the  country,  the  hand- method,  the  pug-mill,  the  ring- 
pit,  and  the  combined  clay-rolls  and  pug-mill  being  used. 
The  hand-method  of  tempering  is  sometimes  used  in  country 
places,  and  the  clay  by  this  process  is  tempered  by  throwing 
the  material  into  a  pile,  and  at  the  same  time  saturating  it  with 
water.  The  pile  of  clay  thus  formed  is  termed  a  "soak  heap," 
and  the  clay  is  allowed  to  soak  for  about  twelve  or  fourteen 
hours,  when  the  hand-temperer  pulls  down  part  of  the  "  soak 
heap"  with  a  hoe  and  thoroughly  wets  the  portion  of  clay 
thrown  down  and  turns  it  over  several  times  with  a  spade,  after 
which  the  clay  is  formed  into  a  small  cone-shaped  pile.  The 
hand-temperer  then  cuts  through  the  small  pile  of  clay  with  a 
tool  termed  a  "slasher,"  and  after  "cutting  and  slashing"  the 
clay  for  a  short  time  in  this  way,  it  is  again  wetted  and  then 
turned  over  with  a  spade,  after  which  it  is  in  condition  for  the 
moulder.  The  usual  work  required  of  the  hand-temperer  is  to 
"throw  up,"  soak,  and  temper  sufficient  clay  to  make  2333 
brick,  and  in  addition  he  is  required  to  wheel  from  the  floor 


MAKING   AND    BURNING   OF    HAND-MADE   BRICK.  89 

and  hack  in  the  drying  shed  about  650  of  the  green  moulded 
brick. 

The  method  of  tempering  clay  with  a  pug-mill  is  so  well- 
known  that  it  is  scarcely  necessary  to  enlarge  upon  it  here ; 
but  a  full  description  of  the  pug-mills  and  ring-pits  and  meth- 
ods used  in  tempering  clay  for  hand-made  brick  will  be  found 
under  the  respective  sub-heads  of  "  Pug-Mills,"  and  "  Ring- 
Pits  "  in  this  chapter.  Before  the  clay  is  ground  by  the  pug- 
mill  it  is  placed  in  a  semi-circular  pit,  and  after  being  covered 
with  water  it  is  allowed  to  soak  over  night.  When  the  pug-mill 
is  operated  by  horse-power,  one  horse  will  grind  sufficient  clay 
in  about  six  hours  to  make  7,000  brick. 

The  ring-pits  employed  for  tempering  clay  have  a  capacity 
for  grinding  and  tempering  sufficient  clay  to  make  14,000 
brick.  The  pits  are  usually  about  two  feet  deep  and  twenty 
feet  in  diameter,  and  the  tempering-wheel,  which  is  about  six 
feet  in  diameter,  is  made  to  revolve  around  the  pit  by  means  of 
suitable  gearing,  which  is  so  arranged  that  as  the  wheel  revolves 
it  is  gradually  thrown  from  the  centre  to  the  circumference  of 
the  tempering  pit,  and  is  afterwards  gradually  again  drawn 
toward  the  center.  Ring-pits  can  be  operated  either  by  horse- 
power or  by  steam-power,  but  in  works  producing  brick  in 
large  quantities  the  latter  method  is  the  one  commonly  em- 
ployed. 

The  object  of  tempering  the  clay  is  to  thoroughly  mix  it,  and 
prepare  the  material  for  the  use  of  the  moulder,  who  must  have 
it  in  a  condition  not  too  soft  nor  yet  too  hard,  but  in  a  suitable 
state  of  plasticity  to  be  easily  and  solidly  moulded  into  brick. 
After  the  clay  has  been  properly  tempered  and  brought  into 
the  desired  state  of  plasticity,  the  next  step  in  the  process  of 
producing  hand-made  brick  is  that  of 

MOULDING   THE    CLAY. 

The  moulder  is  the  head  of  each  moulding  gang;  all  com- 
plaints against  him,  his  wheeler,  or  his  off-bearer  are  made  to 
him,  and  he  sees  that  any  imperfections  in  the  brick  are  rem- 
edied. 


90  BRICK,  TILES    AND   TERRA-COTTA. 

It  is  the  duty  of  each  moulder  to  get  the  moulding  sand  from 
the  sand-pile  and  spread  it  out  in  the  sun  to  dry ;  the  off-bearer 
rakes  the  dried  sand  into  a  pile,  and  sieves  it  into  a  half-barrel, 
called  "the  tub ;"  after  it  is  sieved,  he  wheels  it  into  the  brick- 
shed  and  covers  it,  so  that  no  water  can  get  into  it. 

The  wheeler  gathers  the  stones  and  hard  lumps  of  clay  that 
have  been  thrown  out  by  the  moulder,  and  wheels  them  to  some 
out-of-the-way  place. 

It  is  always  the  custom  for  the  moulder  to  get  the  "  table, 
stool,  and  water  bowl"  in  readiness  before  the  first  day's  make 
of  brick  is  produced,  in  the  commencement  of  the  season,  on 
which  day  none  of  the  hands  in  the  yard  do  more  than  one-half 
the  usual  task ;  twenty  rows  of  brick  are  made,  instead  of  forty  ; 
but  all  hands  are  allowed  and  paid  for  a  full  day's  work. 

It  is  the  duty  of  the  moulder  to  take  entire  care  of  fifteen 
rows  of  the  brick  made  by  him,  and  laid  out  on  the  floor  by 
the  off-bearer ;  the  wheeler  is  also  charged  with  the  care  of 
fifteen  rows,  and  the  off-bearer  with  the  remaining  ten  rows, 
and  the  fraction  of  a  row,  and  the  task  of  no  member  of  the 
moulding  gang  is  completed  until  the  day's  make  of  brick  is 
safely  placed  in  the  drying-shed ;  and  if  portions  are  lost 
through  exposure,  from  the  negligence  of  any  member  of  the 
gang,  the  value  of  such  loss  is  charged  to  him,  and  deducted 
from  his  pay. 

In  addition  to  other  work,  the  moulding  gangs  are  required 
to  keep  the  moulding-floors,  gutters,  and  the  bottom  of  the 
drying-shed  in  good  condition. 

The  moulding  is  conducted  in  different  ways ;  sometimes 
four,  five,  and  even  six  brick  are  moulded  at  one  time ;  but 
the  usual  method  employed  in  the  Eastern  States  and  also  in 
the  Middle  States  is  to  mould  one  brick  at  a  time.  Light,  cast- 
iron  moulds  are  commonly  employed  in  which  to  shape  the 
brick.  The  size  of  the  mould  to  be  employed  depends  largely 
upon  the  nature  of  the  clay  used.  Strong  clays,  because  of 
their  shrinkage,  require  larger  moulds  than  weaker  clays  which 
do  not  shrink  so  much.  The  average  dimensions  of  the  Haver- 


MAKING   AND    BURNING    OF   HAND-MADE   BRICK.  91 

straw  moulds  are  4^  inches  wide,  8%  inches  long,  and  2^5 
deep.  Before  the  operation  or  moulding  commences,  the 
laborer,  called  a  "wheeler,"  brings  the  tempered  clay  to  the 
moulder  and  piles  it  upon  a  wooden  stand  in  front  of  him.  A 
boy,  called  an  "off-bearer,"  takes  the  cast-iron  mould,  and  after 
sanding  the  interior,  hands  it  to  the  moulder,  who,  with  both 
hands,  pulls  down  a  portion  of  the  clay  from  the  stand  or  table, 
and  after  throwing  a  handful  of  moulding  sand  over  the  clay, 
works  the  mass  into  a  peculiar  form,  called  a  "  waulk,"  and  he 
then  dashes  the  "waulk"  with  great  force  into  the  mould,  the 
bottom  of  which  rests  upon  the  cast-iron  moulding  cleat,  as  is 
shown  in  Fig.  I.  The  clay  is  dashed  into  the  mould  by  the 
two  hands  of  the  moulder,  and  the  excess  of  clay  is  then  struck 
off  with  a  "plane,"  which  is  a  tool  resembling  the  trowel  used 
by  plasterers,  and  is  shown  in  Fig.  2,  with  which  he  strikes  off 
the  clay  piled  above  the  top  of  the  mould.  The  boy  or  "off- 


Section  of  cleat 
for  Moulder's  table 


Top  of  table 

bearer"  next  takes  the  mould  containing  the  brick,  and  after 
carrying  it  to  the  "drying-floor"  he  spreads  it  out,  the  brick 
being  relieved  from  the  mould  by  a  gentle  shock,  and  as  the 
"off-bearer"  returns  to  the  moulding-bench,  he  cleanses  the 
inside  of  the  mould  and  especially  the  corners  by  scraping  them 
with  ^a  knife  which  is  carried  suspended  by  a  string  from  the 
boy's  side.  The  mould  is  then  thrown  into  a  tub  containing 
sand  placed  convenient  to  the  moulder,  who,  during  the  time 
which  has  been  required  for  the  boy  to  carry  the  brick  to  the 
drying-floor  and  return,  has  moulded  another  brick,  and  the 
"off-bearer"  takes  this  one  and  spreads  it  alongside  of  the 
other,  and  thus  the  work  continues  until  the  day's  task  has 
been  accomplished.  The  brick  are  generally  spread  out  until 


92  BRICK,  TILES    AND   TERRA-COTTA. 

they  number  58  in  each  row,  and  40  of  these  rows  and  a  frac- 
tion of  one  row  containing  13  brick,  the  whole  comprising 
2,333  brick,  usually  constitute  a  day's  work  for  each  mould- 
ing day.  A  moulding  gang  consists  of  one  laborer  called  the 
"moulder,"  and  one  able-bodied  man  called  the  "  wheeler,"  and 
one  boy  called  the  "  off-bearer."  If  there  is  a  deficiency  in  any 
of  the  respects  in  which  a  good  brick  is  made,  the  owner's  eye 
should  be  able  to  detect  it  and  his  brain  apply  the  proper 
remedy.  For  instance,  a  moulder  makes  a  "  bible  face ;  "  a 
bend  down  in  the  centre  will  usually  correct  the  error.  If  a 
new  hand  makes  a  perfect  brick,  it  invariably  dries  crooked. 
It  will  probably  be  found  that  he  "  palms"  his  brick  heavily  in 
the  centre  only.  Direct  that  he  thereafter  "  palm"  both  heads, 
it  does  not  matter  which  head  first.  Another  man  may  cut  a 
"  raw  face;"  see  that  his  plane  is  worked  level  instead  of  on 
edge,  or  possibly  his  water-bowl  is  kept  too  nearly  empty. 

Watch  the  off-bearing  boys ;  see  that  brick  are  properly 
"bobbed"  (corners  and  edges  settled  with  a  retouch  of  the 
mould)  ;  that  they  learn  to  line  or  match  their  brick  both  ways 
on  the  floor;  and  make  any  advance  in  wages  depend  on  the 
faithful  execution  of  these  details. 

It  happens  many  times  that  the  interests  of  the  proprietor 
force  him  to  notice  points  that  are  new  to  the  owner  of  the  old- 
est pair  of  hands  that  yet  "drove  a  waulk."  A  pug-mill  will 
temper  sufficient  clay  for  three  of  these  gangs,  and  the  day's 
work  of  each  gang  consists  in  moulding  and  wheeling  to  the 
drying  shed  and  there  hacking  2,333  brick. 

DRYING. 

The  brick  generally  remain  upon  the  drying  floor  for  about 
twenty-four  hours,  that  is,  in  good  drying  weather. 

The  first  step  in  the  drying  of  hand-made  brick  is  to  turn 
those  upon  edge  that  were  made  the  day  previous ;  if  there  are 
no  indications  of  rain,  the  brick  are  "turned  up"  early  in  the 
morning,  and  allowed  to  stand  upon  edge,  exposed  to  the  sun, 
until  about  about  four  o'clock  in  the  afternoon,  when  each  man 


MAKING    AND    BURNING    OF    HAND-MADE    BRICK.  93 

"  takes  in  his  share,"  and  carefully  hacks  them  in  the  drying- 
shed  ;  usually  they  are  hacked  about  eight  courses  high  on  the 
edge  and  the  hacks  kept  separate,  to  allow  circulation  of  air. 
There  is  a  space  left  between  the  brick  of  one-half  inch,  and  a 
"head"  or  pier  is  built  at  each  corner  of  the  "  rows." 

If  there  should  be  indication  of  rain  before  the  usual  time  for 
"taking  in  of  the  brick,"  and  any  of  the  brick  are  hard 
enough  to  handle,  they  are  wheeled  into  the  shed ;  if  n'ot  firm 
enough,  they  are  left  to  be  "washed,"  that  is,  the  brick  on 
edge  are  again  laid  flat,  and  the  rain  falls  upon  them. 

Some  clays  will  stand  this,  but  brick  made  of  other  clays 
are  entirely  destroyed,  if  not  by  the  rain,  then  by  the  sun,  as 
they  break  in  half  as  soon  as  the  heat  again  strikes  them. 

Brick  that  will  stand  "washing"  are  wheeled  into  the  shed 
and  set  for  salmon  or  arch  brick,  when  they  go  into  the  kiln. 

The  brick  having  been  exposed  to  the  rain  are  called 
"washed  brick;"  they  have  a  rough  appearance,  and  are  gen- 
erally not  much  esteemed,  but  they  make  the  strongest  brick 
that  come  out  of  a  kiln ;  and  when  hard-burned,  they  have  no 
equal  for  foundation  or  sewer  work.* 

After  being  exposed  to  the  action  of  the  sun  for  a  sufficient 
length  of  time,  each  member  of  the  moulding  gang  carries  a 
certain  number  of  the  brick  to  the  drying  shed  and  hacks  them 
upon  edge.  It  is  the  custom  to  construct  the  drying-shed  im- 
mediately adjoining  the  brick  floors,  and  these  sheds  are  built 
in  a  cheap  manner.  The  usual  measurement  is  about  28  ft.  in 
width  between  the  outside  posts,  and  the  height  on  the  side 
adjoining  the  brick  floors  is  about  4^  ft.,  and  from  these  low 
sides  the  pitch  of  the  roof  runs  to  an  incline  of  about  35  de- 
grees on  each  side  of  the  ridge-pole,  which  is  supported  by 
chestnut  posts  planted  in  the  centre  of  the  shed.  The  roof  of 
the  drying-shed  requires  to  be  constructed  in  such  a  manner 
that  there  will  be  no  drip  from  the  boards  which  form  the  roof, 
as  the  brick  which  the  shed  will  contain  would  thereby  be 
ruined.  It  is  the  custom  in  constructing  these  drying-sheds  to 
put  them  up  in  a  temporary  manner,  and  the  roof  is  formed  by 


94  BRICK,  TILES   AND   TERRA-COTTA. 

extending  the  boards  from  the  stringers  at  the  sides,  or  low 
parts  of  the  shed,  and  allowing  them  to  rest  upon  the  ridge- 
pole, the  bottom  boards  being  separated  sufficiently  far  to  be 
covered  with  a  lap-board.  It  is  essential  that  no  support  of 
any  kind  should  be  placed  between  the  ridge-pole  and  the 
stringers  at  the  sides  of  the  sheds,  for  the  water  which  falls  upon 
these  temporary  roofs  not  only  runs  down  the  top  of  the  board, 
but  also  follows  the  under  side ;  and  should  this  water  in  its 
passage  meet  any  obstruction,  like  a  stringer  or  support  of  any 
kind,  before  it  should  reach  the  end  of  the  board,  the  water 
would  thus  drip  into  the  drying  shed  and  ruin  the  bottom  of 
the  shed,  as  well  as  the  brick  which  might  be  hacked  therein. 
The  boards  which  form  the  roofs  of  these  temporary  sheds 
should  be  free  from  large  or  loose  knots,  and  wane  edges, 
which  are  liable  to  split  and  thus  form  drips.  The  board  roofs 
over  these  drying  sheds  commonly  sags  in  the  centre,  but  if  the 
boards  are  of  good  quality  and  free  from  the  imperfections 
which  we  have  above  mentioned,  it  is  seldom  that  water  finds 
its  way  into  the  shed,  or  that  the  boards  break  on  account  of 
this  sagging.  It  is  customary  to  close  the  ends  of  the  sheds 
with  boards,  but  the  sides  are  commonly  left  open  for  the  free 
admission  of  air ;  light  battened  doors  hung  on  leather  hinges 
are  sometimes  used  to  protect  the  sides  from  driving  rains. 
The  period  which  the  hand-made  brick  remain  in  these  drying 
sheds  is  usually  about  two  or  three  weeks,  but  during  rainy 
seasons  a  longer  time  is,  oi  course,  required.  Improved  forms 
of  drying  sheds  are  so  constructed  that  the  roof  can  be  made  to 
open  in  sections,  thus  exposing  the  hacks  of  green  brick  to  the 
direct  action  of  the  heat  of  the  sun. 

When  brick  are  moulded  by  what  is  known  as  the  "slop" 
method,  they  are  sometimes  hacked  upon  the  drying  floors  by 
means  of  "pallets."  In  the  "slop"  method  of  moulding,  the 
moulds  are  wetted  with  water  instead  of  being  sanded  as  we 
have  before  described.  "  Pallets"  are  flat  boards,  each  of  which 
holds  about  five  or  six  brick,  and  by  means  of  cleats  at  each 
end  the  green  brick  are  prevented  from  being  crushed  by  the 


MAKING    AND    BURNING   OF   HAND-MADE   BRICK.  95 

piling  of  one  "  pallet"  above  another.     After  the  stock  has  been 
properly  dried,  the  next  operation  is  that  of 

SETTING  THE  GREEN  BRICK  IN  THE  KILN. 

The  brick  having  been  moulded  and  dried,  the  next  step  is 
that  of  setting  or  placing  them  in  the  kiln  preparatory  to  burn- 
ing, which  work  is  generally  done  by  task,  and  usually  by  a 
force  of  five  men,  called  the  "setting  gang,"  which  is  composed 
of  one  foreman  called  the  "  setter,"  and  four  men  who  bring  the 
brick  to  him  called  the  "wheelers  and  tossers." 

A  day's  work  for  this  gang  is  to  take  20,000  brick  out  of 
the  sheds,  wheel  them  to  the  kiln  and  toss  them  to  the  setter, 
who  places  them  in  a  proper  manner  for  burning. 

In  a  kiln  the  first  brick  set  are  in  the  back  arch,  and  arch 
brick  in  setting  are  divided  in  four  classes,  viz :  the  straight 
courses,  pillar,  hangers,  and  skintle  brick,  the  names  depend- 
ing upon  the  position  which  they  occupy  in  the  arch. 

The  arch  is  generally  fourteen  courses  high,  the  brick  being 
set  on  edge  and  one-half  inch  apart ;  the  bottom  eight  courses 
of  the  arch  are  usually  called  the  u  straight  courses,"  on  the 
top  of  which  are  placed  the  projecting  six  courses  forming  the 
arch,  and  which  are  called  the  "over-hangers." 

The  "pillar"  brick  are  the  ones  between  the  straight 
courses,  and  the  "skintles"  are  the  brick  set  diagonally  in 
order  to  tie  the  over-hangers  together,  as  shown  in  Fig.  3. 

^-' 
FIG.  3. 


Skintle 


The  row  of  brick  first  set  on  the  top  of  the  arch  is  called  the 
"tie  course,"  and  the  fourteen  courses,  including  the  "tie 
course  "  first  set  041  the  top  of  the  arch,  are  called  the  "  lower 
bench,"  and  next  fourteen  courses,  which  usually  finish  the 
height  of  the  kiln,  are  called  the  "  upper  bench."  "  Forty-two 


96 


BRICK,  TILES    AND   TERRA-COTTA. 


high"   is  the  way  that  the  height  of  the  kiln  is  described,  and 
this  is  the  usual  height. 

Fig.  4  shows  ten  courses  of  common  brick  set  on  the  bench 
in  the  kiln,  so  placed  as  to  preserve  one  uncrossed  face  to  each 
brick.  The  arch,  lower  and  upper  benches,  having  been  set, 
there  is  a  brick  laid  flat  on  the  topmost  brick;  this  brick  is 
called  the  "  raw  platting;"  then  on  the  top  of  the  raw  platting 
a  burned  brick  is  laid  reversed  way  across  it ;  this  is  called  the 
"  burnt  platting." 

FIG.  4. 


It  is  the  duty  of  the  setting  gang,  in  addition  to  placing  the 
twenty  thousand  brick  in  the  kiln,  to  "  platt"  it,  and  then  cover 
up  the  face  of  the  raw  brick  with  boards  on  end ;  this  process 
is  called  "  facing  up." 

In  this  manner  the  kiln  is  "set  out,"  or  filled  with  green 
brick,  and  sometimes  two,  three,  and  even  four  setting  gangs 
are  simultaneously  at  work  in  the  same  kiln  if  there  is  a  great 
demand  for  the  brick. 

Before  any  brick  are  set  into  a  kiln  it  is  plastered  or  daubed 
all  over  the  inside  face  with  mud  in  order  to  stop  any  cracks 
that  there  may  be  in  the  face  of  the  walls,  and  to  hold  the  heat 
when  the  kiln  is  on  fire.  For  this  work  one  dollar  and  twenty- 
five  cents  is  paid  for  a  small  kiln  holding  one  hundred  and  sixty 
thousand  brick,  and  two  dollars  and  fifty  cents  for  a  kiln  hold- 
ing one-half  million  of  brick.  The  brick  having  all  been 
placed  in  the  kiln,  the  opening  through  which  the  brick  are 
wheeled  into  the  kiln,  and  hauled  out  after  burning,  is  closed  or 
walled  up. 

This  opening  is   called   a  "facing,"  "bestowing,"  or  "  abut- 


MAKING   AND    BURNING    OF    HAND-MADE    BRICK.  97 

ment,"  and   the   process   of  walling  it  is  termed  "  closing  the 
bestowing." 

The  wall  of  the  bestowing  is  built  in  two  thicknesses  of 
brick;  the  first  or  inner  one  is  put  up  and  "daubed"  or  plas- 
tered over ;  then  the  second  or  outer  thickness  is  built  and 
"daubed."  Care  is  taken  in  this  operation  to  prevent  air  from 
entering  and  lowering  the  temperature  of  the  kiln. 

The  gang  that  puts  up,  daubs,  and  props  the  "bestowing" 
is  allowed  one-half  day  each  man. 

A  good  setting  gang  can  commence  work  at  five  o'clock  in 
the  morning  and  place  20,000  brick  in  the  kiln,  and  have  their 
task  completed  by  mid-day. 

The  brick  having  next  been  made  and  set,  are  ready  to  be 
burned  and  converted  from  a  perishable  into  an  imperishable 
substance. 

BURNING. 

The  high  price  of  wood  in  and  near  large  cities  makes  it  as  a 
rule  entirely  out  of  the  question  to  use  it  generally  for  burning 
brick  in  such  localities. 

The  process  of  burning  by  coal  is  the  one  that  we  shall  de- 
scribe ;  the  principle  is  the  same  as  for  wood,  the  agents  em- 
ployed to  produce  the  heat  being  the  only  difference. 

Brick-kilns  requiring  wood  for  fuel  are  flat  in  the  bottom  and 
paved  with  brick;  coal-kilns  have  part  of  this  pavement  cut 
away  under  the  portion  which  is  to  form  the  arch  of  the  kiln 
and  the  place  filled  with  grates,  and  under  each  of  the  grates 
there  is  a  trench  dug  all  the  way  through  the  kiln,  called  the 
"  ash-pit."  A  space  at  each  side  of  the  kiln,  is  dug  out  to  the 
depth  of  the  ash-pits,  the  top  covered  with  a  slanting  shed,  and 
the  space  is  called  the  "  kiln  shelter,"  and  serves  as  shelter  for 
the  laborers  and  fuel  while  the  kiln  of  brick  is  being  burned. 
Before  fire  is  placed  in  the  coal-kiln  the  ashes  made  in  burning 
the  previous  kiln  of  brick  are  drawn  out  of  the  pits  into  the 
kiln  shelter,  thrown  into  wheelbarrows  and  carried  out  of  the 
way,  and  after  fire  is  started  in  the  kiln  the  ashes  are  drawn 
each  day. 
7 


98  BRICK,  TILES    AND   TERRA-COTTA. 

The  roof  over  the  kiln  is  next  examined  to  see  that  it  is  not 
leaky,  and  then  every  alternate  brick  which  was  laid  flat,  and 
called  the  "burnt  platting,"  is  stood  upon  its  end,  this  being 
done  in  order  to  allow  the  steam,  or  as  it  is  called  in  burning, 
the  "water  smoke,"  to  escape  as  rapidly  as  possible. 

The  platting  having  been  raised,  the  next  step  is  to  start  a 
small  fire  in  the  mouth  of  each  arch,  using  light  splintered 
wood,  and  building  it  up  with  lumps  of  coal ;  the  fire  should 
be  started  on  the  side  of  the  kiln  that  will  allow  the  smoke  to 
be  blown  by  any  wind  entirely  through  the  arches  of  the  kiln. 

After  the  fires  have  been  started  in  the  mouth  of  all  the 
arches  on  the  windward  side  of  the  kiln,  they  are  next  made  in 
the  mouth  of  the  arches  on  the  opposite  side. 

The  fires  are  built  up  gradually  from  each  side  until  they 
meet  in  the  centre  of  the  kiln,  and  this  is  called  "  crossing  the 
fires." 

The  fires  should  be  "crossed"  much  more  slowly  for  dry  or 
damp  clay  machine-made  brick  than  for  hand-made  brick. 

When  brick  produced  by  the  hand  process  are  well  dried, 
and  there  is  no  dampness  in  the  bottom  of  the  kiln  or  in  the 
ash-pits,  the  fires  can  be  crossed  in  forty-eight  hours ;  but  for 
machine-made  brick  they  should  never  be  crossed  inside  of 
seventy-two  hours. 

It  should  be  noticed  that  the  steam,  or  "  water  smoke,"  is 
freely  coming  out  of  the  top  of  the  kiln  from  the  time  that  fire 
is  put  into  it. 

The  fires  are  gradually  increased  until  the  fifth  day,  or  say, 
in  other  words,  the  one  hundred  and  twentieth  hour  after  set- 
ting fire ;  by  this  time  the  "  water  smoke"  or  steam  from  the 
top  of  the  kiln  should  have  changed  from  a  white,  watery,  into 
a  bluish  black  smoke,  and  the  fire  should  in  the  night-time  be 
seen  plainly  coming  through  the  top. 

At  this  period  the  kiln  is  said  to  be  "hot,"  and  the  brick  are 
now  ready  to  shrink,  or  as  it  is  termed  in  burning,  to  "  settle," 
and  all  the  platting  is  put  down  and  tightened.  Care  must,  to 
this  point,  have  been  observed  to  increase  by  degrees  the  heat, 


MAKING  AND    BURNING   OF   HAND-MADE   BRICK.  99 

the  firing  having  been   gradually  reduced  from  four  hours  to 
about  two  hours  between  fires  at  this  stage. 

The  fires  that  the  brick  are  now  to  receive  are  the  most  in- 
tense and  the  heaviest  that  will  be  applied  to  them ;   the  oxide 
of  iron  is  now  to  be  converted  into  peroxide,  or,  as 
the  men  around  the  kiln  would  call  it,  "  the  brick  are 


to  be  painted  red." 

Before  these  fires  are  given,  a  long  iron  rod,  a  little 
longer  than  one-half  the  width  of  the  kiln,  having  a 
flat,  nearly  circular  piece  at  the  one  end,  open  in  the 
centre,  and  having  an  iron  handle  at  the  other  end, 
as  shown  in  Fig.  5,  is  run  on  top  of  the  grates  and 
under  the  fires  to  loosen  them. 

The  instrument  is  called  a  "  moon,"  and  its  object 
is  to  enliven  the  fires  and  to  get  rid  of  the  ashes,  as 
well  as  to  break  up  the  clinkers. 

After  "running  the  moon"  into  all  the  arches  of 
the  kiln,  the  latter  are  allowed  to  wait,  or  cool,  for 
twenty  minutes  or  so,  when  the  arch  first  mooned  is 
fired  from  both  sides  at  the  same  titrte.  The  amount 
of  coal  thrown  uniformly  through  each  arch  varies 
with  the  condition  of  each  particular  arch.  An  arch  that  is 
very  hot  is  not  fired  so  hard  as  one  that  is  cooler. 

The  usual  amount  of  coal  thrown  into  each  arch  in  these 
settling  fires  is  about  from  thirty-two  to  forty  shovels  full  for  a 
kiln  containing  200,000  brick,  that  is,  from  sixteen  to  twenty 
shovels  full  for  each  door  on  each  side  of  the  kiln.  Before  these 
fires  are  given,  the  doors  in  the  ash-pits  are  closed,  and  kept 
closed  for  about  five  minutes  after  the  last  arch  is  fired.  Any 
"cold  "  place  in  the  kiln  can  now  be  detected  by  the  black  smoke 
not  freely  issuing  from  it,  which  can  be  seen  from  the  top  of 
the  kiln.  A  few  shovels  full  of  coals  are  now  thrown  into  the 
arches  under  these  places. 

The  doors  to  the  mouths  of  the  arches  are  closed  soon  after 
the  fires  are  crossed  ;  if  an  arch  is  too  hot,  the  door  is  opened 
a  little,  which  is  called  "  cracking  the  door." 


UNIVERSITY 


100  BRICK,  TILES   AND   TERRA-COTTA. 

It  is  a  difficult  question  to  determine  when  and  how  much 
air  to  admit  into  a  kiln  during  the  process  of  burning.  Air  in 
proper  quantities  may  often  be  admitted  advantageously  above 
the  burning  fuel.  After  the  gases  are  superheated  in  their 
passage  through  the  heat  chambers,  then  near  where  the  heat 
enters  the  kiln  proper  there  should  be  admitted  as  much  oxy- 
gen as  the  heated  air  will  absorb  without  reducing  the  heat,  as 
it  enters  the  kiln,  below  the  degree  required  for  the  burning  of 
the  brick.  This  can  be  regulated  by  admitting  more  or  less  air 
and  a  careful  observation  of  the  heat.  One  skilled  in  burning 
brick  knows  at  a  glance  whether  he  has  the  proper  degree  of 
heat  or  not.  After  the  proper  amount  of  air  has  been  admitted 
above  and  below  the  grates  in  the  furnace,  the  amount  ad- 
mitted below  being  regulated  by  the  ash-pit  door,  then  again 
near  the  point  of  contact  with  the  brick,  admit  just  as  much  as 
it  will  bear.  We  have  then  done  all  that  can  be  done  in  this 
direction ;  the  quantity  is  to  be  determined  by  the  burner  and 
adjusted  to  suit  the  quality  of  the  fuel  and  the  condition  of  the 
kiln  at  the  different  stages  of  burning. 

The  "  settling  fires "  are  given  to  the  kiln  about  every  two 
hours,  unless  it  happens  that  the  wind  and  rain  keep  the  heat 
down  in  the  arches,  in  which  case  the  firing  is  delayed  until  the 
arches  are  cool  enough  to  receive  them. 

After  the  kiln  is  "  burned  off,"  all  the  doors  and  all  the  cracks 
are  plastered,  and  the  kiln  remains  closed  for  five  days. 

If  the  arches  are  fired  too  hot,  they  will  "  run  "  or  stick  to- 
gether. Some  kilns  have  very  high  stationary  roofs,  others 
have  movable  roofs  that  slide  on  railroad  tracks  from  one  kiln 
to  another ;  but  the  majority  of  open  or  Dutch  kilns  have  only 
temporary  roofs,  which  are  taken  off  when  the  kiln  gets  "hot," 
which  is,  as  has  been  stated,  about  the  fifth  day. 

No  rule  can  be  laid  down  to  determine  when  the  kiln  of  brick 
has  settled  sufficiently,  that  is,  sunk ;  the  proper  amount  of 
settling  is  known  only  by  experience  with  the  clay ;  but  for 
moderately  strong  clay,  it  is  about  seven-and-one-half  per  cent, 
of  the  height. 


MAKING   AND    BURNING    OF    HAND -MADE   BRICK.  IOI 

For  instance,  say  a  kiln  of  brick  is  made  of  moderately  strong 
clay,  and  set  forty-two  high  in  the  kiln,  and  the  brick  measure 
four-and-one-half  inches  in  width,  the  total  height  would  be  one 
hundred  and  eighty-nine  inches,  and  seven  and  one-half  per 
cent,  would  be  a  little  over  fourteen  inches.  Many  classes  of 
weak  clays  for  the  same  sized  kiln  could  be  settled  only  about 
seven  inches,  and  still  make  good  building  brick. 

For  information  as  to  the  nature  of  clays  the  reader  is  referred 
to  Chapter  II.,  which  treats  of  the  different  varieties. 

The  kiln  which  has  been  described  in  burning  is  the  ordinary 
open  Dutch  kiln.  We  selected  that  class  of  kilns  for  describing 
the  process  because  they  are,  unfortunately,  the  ones  that  are 
generally  used.  There  are  various  other  kinds  of  kilns,  many 
of  which  are  decided  improvements,  especially  in  the  economy 
of  fuel. 

Many  of  the  annular  kilns  are  very  economical  in  the  con- 
sumption of  fuel ;  but  kilns  of  this  kind  have  usually  other  dis- 
advantages which  offset  the  saving  of  fuel.  The  over  or  down 
draught  kiln  is  an  excellent  improvement. 

There  are  other  methods  for  burning  brick,  such  as  by  com- 
binations of  gas  and  air,  combinations  of  air  and  gaseous  fuels, 
and  by  the  use  of  natural  gas  and  petroleum  for  fuel,  and  other 
devices,  which,  although  they  are  all  good,  require  a  highly 
scientific  knowledge  of  heat,  its  mechanical  action,  and  many 
other  things. 

The  amount  of  coal  required  to  burn  a  kiln  of  hand-made 
brick  is  usually  about  one-quarter  of  a  ton  to  one  thousand 
brick;  but  for  dry-clay  brick  a  larger  quantity  is  'required,  the 
amount  being  about  one-third  of  a  ton  to  one  thousand  brick, 
which  applies  in  both  cases  to  the  open  top  or  Dutch  kiln,  but 
when  more  economical  forms  of  kilns  are  employed  the  con- 
sumption of  fuel  is  much  less. 

TOOLS   AND  APPLIANCES  USED  IN  THE  MANUFACTURE   OF    HAND-MADE    BRICK. 

The  tools  and  appliances  used  by  a  hand-made  brick  gang, 
in  addition  to  those  which  have  been  mentioned,  are  as  'follows, 
viz :  — 


102 


BRICK,  TILES    AND   TERRA-COTTA. 


FIG.  6. 


One  Ames's  spade,  No.  2,  for  wheeler. 
One  clay  barrow  for  wheeler. 
One  sieve,  No.  42,  for  off-bearer. 
One  brick  barrow  for  off-bearer. 
One  brick  barrow  for  moulder. 

There  is  a  tool  used  for  scraping  off  and  levelling  the  mould- 
ing floor,  and  levelling  the  bottom  of  the  drying-shed  prepara- 
tory to  hacking  the  brick.  It  consists  of  a 
piece  of  light  pine  board,  one  inch  thick, 
twenty  inches  long  by  six  inches  wide,  set 
upright,  with  a  long  light  handle  in  the 
centre.  At  the  bottom  is  tacked  a  thin  piece 
of  steel,  generally  an  old  wood-saw  blade, 
with  the  teeth  turned  upward,  and  the  smooth 
edge  forming  the  bottom. 

This  tool  is  never  furnished  by  the  pro- 
prietor of  the  yard,  it  is  always  the  private 
property  of  the  moulder.  The  tool  is  called 
a  "  lute,"  and  it  is  shown  in  Fig.  6. 

The  time  of  the  men  around  the  burning 
kiln  is  divided  into  periods  called  "watches ;" 
a  watch  is  two  days  and  a  night,  that  is,  a 
man  starts  to  work  on  a  kiln,  say  at  six 
o'clock  in  the  morning;  he  stays  that  day 
and  night,  and  the  next  day  until  five  o'clock 
in  the  afternoon,  at  which  time  he  is  relieved.  After  resting 
that  night,  he  is  at  the  kiln  the  next  morning,  and  takes  another 
watch  of  two  days  and  a  night;  the  time  made  at  night  is 
counted  as  a  day  extra. 

The  centre  of  a  kiln  settles  first  in  burning,  after  which  the 
settling  fires  are  put  close  to  the  mouth  of  the  arches,  no  coal 
being  thrown  in  the  centre ;  the  fires  in  the  mouths  are  called 
"head  fires."  To  enliven  these  fires  a  "short  moon"  is  used, 
and  it  is  similar  to  the  long  moon  described  before,  and  shown 
in  Fig.  5,  the  difference  being  only  in  the  length  of  the  handle. 
In  addition  to  the  long  and  short  moons,  another  tool,  called 


Moulder' sLute 


MAKING   AND    BURNING   OF.   HAND-MADE   BRICK.  103 

a  rake,  is  used ;  it  is  as  long  as  the  long  moon,  and  has  teeth 
three-quarters  of  an  inch  in  diameter,  and  four  inches  long,  set 
into  a  back  of  iron  ten  inches  long,  two  inches  wide,  and  three- 
quarters  thick. 

Soft  coal  increases  in  bulk  after  being  fired,  and  the  rake  is 
used  for  levelling  the  high  places  in  the  fires  of  the  arches  of 
the  kiln. 

A  sledge-hammer,  weighing  about  ten  pounds,  is  used  for 
breaking  up  the  large  lumps  of  coal,  fine  coal  being  used  for 
settling  the  kiln. 

For  each  kiln  hand  there  is  required  a  small  furnace  shovel 
or  "  scoop,"  for  firing,  and  in  addition,  two  large  coal  shovels 
for  general  use  in  throwing  the  coal  into  the  kiln-shelter  and 
spreading  it  along  in  front  of  the  arches. 

A  rough  ladder  for  climbing  about  the  kiln  is  also  necessary, 
as  well  as  two  stout  water  buckets  in  which  to  carry  the  mud, 
or  "daub,"  used  for  plastering  over  all  the  cracks  which  appear 
as  soon  as  the  kiln  commences  to  get  hot. 

It  is  often  necessary  to  place  a  barricade  of  boards  around 
the  kiln-shelters,  and  often  around ^some  part  of  the  top  of  the 
kiln  during  periods  of  high  winds,  and  lumber  and  nails  suffi- 
cient for  erecting  this  barricade  should  be  kept  on  hand. 

PUG-MILLS. 

The  pug-mill  is  an  iron  shaft  with  knives  of  the  same  material 
about  eighteen  inches  long,  two  and  a  half  inches  wide,  and 
three-eighths  of  an  inch  thick,  extending  from  the  shaft  in  four 
directions,  but  so  placed  that  one  does  not  follow  directly  under 
the  other.  To  trace  the  knives  around  the  shaft  would  be  like 
following  the  thread  of  a  screw.  At  the  bottom  of  this  shaft, 
and  all  on  the  same  level  following  consecutively  are  four 
broad,  curved  pieces  of  iron,  called  sweeps,  pressers,  or  pushers, 
which  terms  are  synonymous,  and  their  use  is  to  force  the  tem- 
pered clay  through  an  opening  near  the  bottom,  in  the  side  of 
the  cylinder  or  box  inclosing  the  pug-mill. 

Sometimes   the  casing  which  incloses  the   pug-mill  is  made 


104  BRICK,  TILES   AND   TERRA-COTTA. 

square  and  of  wood,  two  inches  thick  usually,  leaving  the  clay 
to  pack  into  the  square  corners ;  at  other  times  the  cylinder  is 
formed  of  iron,  cast  in  sections  and  bolted  together.  In  the 
Southern  States  the  entire  arrangement  of  upright  shaft,  knives, 
and  pressers  is  more  often  called  a  "hopper"  than  a  pug-mill. 

The  well-knawn  manufacturers  of  brick  and  tile  yard  sup- 
plies— The  Frey-Sheckler  Co.,  of  Bucyrus,  Ohio — through 
whom  all  the  tools  and  appliances  named  in  this  chapter  can  be 
ordered,  make  four  regular  sizes  of  improved  pug-mills,  also 
special  sizes  of  pug-mills  designed  to  suit  any  yard  devoted  to 
the  manufacture  of  building-brick,  fire-brick,  terra-cotta,  or  tiles. 

Mr.  Alfred  Hall,  of  Perth  Amboy,  N.  J.,  has  invented  an 
improvement  in  the  construction  of  pug-mills  used  in  the  man- 
ufacture of  brick,  terra-cotta,  fire-clay  wares,  and  pottery,  the 
novelty  of  which  consists  in  the  construction  and  arrangement 
of  parts  in  regard  to  the  vertical  revolving  shaft  and  the  blades 
or  knives. 

This  invention  consists  in  a  peculiar  blade  or  arm  (shown  in 
perspective  in  Fig.  8)  and  a  shaft  having  a  special  and  peculiar 
mortise,  into  which  the  arm  or  knife  is  secured. 

Fig.  7  is  a  vertical  central  section ;  Fig.  8,  a  perspective  de- 
tail of  one  of  the  arms  or  knives ;  Fig.  9,  details  of  the  parts 
separated,  showing  their  relative  formation. 

A  is  the  vertical  shaft,  to  be  placed  in  any  suitable  cylinder 
for  holding  the  material  to  be  operated  upon.  It  is  supported 
in  position  by  the  framing,  so  that  it  can  be  readily  revolved. 
It  has  formed  in  it  a  series  of  cross  or  horizontal  mortises,  B, 
each  adapted  to  hold  the  tenon  D  of  the  blade  C.  Each  mortise 
B  has  its  upper  side  made  on  a  horizontal  line,  while  its  lower 
surface,  b>  is  inclined  downward  from  the  outer  end  inward  to  or 
nearly  to  the  centre  of  the  shaft,  thus  giving  to  the  mortise  the 
shape  or  form  in  its  vertical  width  of  a  half-dovetail.  The 
tenon  D  of  the  blade  C  is  made  in  form  corresponding  to  the 
shape  of  the  mortise  B — that  is,  its  under  face,  d,  is  cut  away 
so  as  to  give  it  an  upward  incline  from  the  outer  end  to  the 
inner  end  of  the  blade  proper,  and  its  outer  end  is  made  of 


MAKING   AND    BURNING    OF   HAND-MADE   BRICK. 


105 


such  size  that  it  will  just  fit  and  enter  snugly  into  the  mouth  or 
outer  end  of  the  mortise.  As  the  tenon  is  pushed  further  into 
the  mortise  it  drops  downward  on  the  inclined  surface  b  and 
away  from  the  upper  side  of  the  mortise,  and  leaves  a  space 
above  it,  into  which  the  key  E  is  driven.  When  the  tenon  and 
key  are  both  inserted  the  blade  will  not  work  loose,  because 


FIG.  7. 


FIG.  8. 


FIG.  9. 


the  inclined  surface  b  and  the  increasing  thickness  of  the  tenon 
operate  to  give  increasing  force  to  hold  the  blade  against  any 
movements  tending  to  draw  the  blade  outward.  The  material 
which  is  being  acted  upon  will  exert  a  pressure  on  the  ends  of 
the  keys  E  and  prevent  them  from  working  loose.  The  blade 
C  has  its  under  face  flat  or  made  to  a  horizontal  plane.  Its 
upper  side  is  gradually  thickened  from  the  edges  to  a  line 
drawn  diagonally  from  the  middle  of  the  outer  end  to  a  point 


106  BRICK,  TILES   AND   TERRA-COTTA. 

on  the  inner  end  next  the  tenon,  midway  between  the  middle 
of  the  blade  and  the  rear  edge. 

In  Fig.  8  the  dotted  line  x  x  represents  the  middle  line  of 
the  blade.  .  The  diagonal  line  c1  c'-  is  the  line  of  greatest  thick- 
ness of  the  blade.  The  blade  thus  formed  provides  an  up- 
wardly-inclined -front  face,  c,  which  is  wider  at  its  inner  end 
next  the  shaft  and  narrower  at  its  outer  end.  The  rear  face,  c1, 
is  wider  at  its  outer  end  than  at  its  inner  end.  The  peculiar 
construction  of  the  blade  gives  much  better  results  in  mixing 
the  material  in  the  cylinder  or  pits.  The  material  is  sooner 
brought  into  a  homogeneous  mass  and  into  the  required  con- 
dition for  the  moulds. 

The  key  E  is  preferably  wedge-shape,  as  shown. 

/  are  the  lower  scrapers,  which  are  provided  with  tenons  of 
half-dovetailed  form,  and  are  secured  in  the  shaft  in  the  same 
manner  as  the  blades  C. 

In  case  of  accidental  breaking  of  one  of  the  blades  the  broken 
blade  can  easily  be  removed  and  another  one  substituted. 

The  pug-mill  and  cylinder  inclosing  are  so  placed  that  the 
pivot  or  spindle  at  the  bottom  of  the  mill  will  be  in  the  centre 
of  the  diameter  of  a  semicircular  pit  which,  to  contain  the  clay 
for  three  gangs,  measures  eight  feet  from  the  centre  of  the  pug- 
mill  shaft  to  the  edge  or  brick  face  of  the  pit,  which  is  four  feet 
deep. 

This  semicircular  pit  is  usually  walled  around  with  brick, 
which  should  be  hard  burned,  and  the  bottom  formed  of  two- 
inch  oak  planks,  cut  wedge-shape. 

Directly  in  front  of  the  pug-mill  there  is  a  fan-shaped  hole  or 
pit,  which  allows  the  wheeler  to  cut  the  clay  away  with  a  spade 
as  it  issues  from  the  hole  in  the  side  of  the  cylinder  at  the 
bottom,  inclosing  the  mill.  If  the  pug-mill  is  turned  by  a 
horse,  it  is  usual,  if  the  clay  bank  is  too  far  away  to  be  con- 
veniently filled  with  wheel-barrows,  to  harness  the  animal  to  a 
cart,  and  haul  the  clay  to  fill  the  pit,  after  the  work  of  grinding 
has  been  completed,  which  usually  requires  about  six  hours. 
A  long  pole  fixed  in  a  yoke  in  the  top  of  the  shaft  is  the  lever- 
age by  which  the  pug-mill  shaft  and  knives  are  turned. 


MAKING    AND    BURNING   OF    HAND-MADE    BRICK.  IO/ 

The  pit  around  the  pug-mill,  when  the  clay  is  ground  by 
horse  power,  holds  usually  material  sufficient  to  make  seven 
thousand  brick ;  after  the  pit  has  been  filled  it  is  the  duty  of 
the  temperer  to  see  that  sufficient  water  is  let  to  the  clay  to 
soak  it. 

The  clay  in  the  pit  is  left  to  soak  over  night,  and  in  the 
morning  the  temperer  gets  into  the  pit  of  mud,  and  first  digs  a 
hole  in  the  clay,  next  to  the  pug-mill,  throwing  the  material 
into  the  mill. 

It  is  necessary  to  grind  the  same  clay  through  the  pug-mill 
several  times,  the  first  thing  in  the  morning,  before  it  comes  to 
the  proper  degree  of  plasticfty  for  moulding ;  this  operation  is 
called  "  sizing  the  clay." 

The  temperer  having  secured  the  proper  plasticity,  or  "size" 
for  the  clay,  he  continues  to  shovel  the  mud  into  the  pug-mill, 
each  wheeler  of  a  gang,  in  turn,  spading  it  away  from  the 
bottom  of  the  pug-mill,  as  it  is  forced  through  the  orifice  at  the 
base  of  the  cylinder. 

During  this  process  of  tempering,  a  small  stream  of  water  is 
continually  running  into  a  barrel  sunk  into  the  ground,  near 
the  box  of  the  pug-mill ;  if  some  of  the  clay  is  very  hard,  there 
is  used  a  large  quantity  of  the  water  from  the  barrel ;  but  if  it 
is  soft,  only  a  small  quantity  of  water  is  used. 

Sometimes  mud,  seemingly  almost  slush,  will  be  thrown  into 
the  pug-mill ;  but  when  it  issues  at  the  bottom,  it  is  stiff  and 
firm ;  when  this  is  done,  the  men  call  it  "  grinding  the  water 
out  of  the  clay;"  but  it  is  really  grinding  the  water  into  the 
clay,  and  thoroughly  mixing  it. 

The  work  of  the  temperer  for  the  pug-mill  is  confined  en- 
tirely to  the  clay  in  the  pit,  and  he  has  nothing  to  do  with 
handling  any  brick,  as  is  the  case  with  the  hand-temperer  be- 
fore mentioned. 

The  pug-mills  are  sometimes  driven  by  steam-power,  instead 
of  being  turned  by  horse ;  in  case  they  are  driven  by  steam, 
there  is  a  large  bevel-wheel  placed  on  the  top  of  the  pug-mill 
shaft,  which  bevel-wheel  gears  into  a  smaller  pinion  on  a  shaft 
keyed  to  a  large  pulley. 


108  BRICK,  TILES    AND    TERRA-COTTA. 

The  pulley  on  the  pug-mill  of  this  character  is  generally 
about  five  feet  in  diameter,  and  eight  inches  face ;  if  the  pulley 
is  too  small  in  diameter,  the  mill  is  liable  at  times  to  clog  and 
stop,  leaving  the  belt  either  to  slip  or  break. 

When  a  machine  of  this  kind  is  used  for  tempering  clay,  the 
pit  which  surrounds  it  can  be  enlarged  to  any  reasonable  ex- 
tent, to  meet  the  requirements  of  a  yard  of  almost  any  size. 

The  power  of  the  small  pinion  into  the  large  bevel-gear 
wheel  is  usually  about  one  into  six;  i.  e.,  the  pinion  makes  six 
revolutions  while  the  wheel  into  which  it  meshes  makes  but  one 
revolution. 

The  quantity  of  thoroughly  tempered  clay  which  a  mill  of 
this  kind  will  turn  out  is  surprising ;  four  men  constantly 
shoveling  clay  into  it  cannot  overstock  it,  if  it  is  going  at  any 
kind  of  quick  speed. 

The  speed  can  be  regulated  so  as  to  travel  at  any  required 
gait ;  but  when  it  is  intended  for  fast  work,  the  pushers  at  the 
bottom  of  the  pug-mill  shaft  must  be  very  strong,  and  securely 
braced  together  with  one-half  inch  iron  rods. 

The  temperers  who  work  at  the  pug-mills  must  be  very  able 
men,  and  thoroughly  understand  their  business,  and  the  nature 
of  the  clay  in  which  they  are  working. 

The  tools  used  for  each  temperer  are  one  Ames  shovel  No. 
2,  one  hilling  hoe,  same  as  that  used  by  the  hand-temperer,  and 
one  bucket. 

The  pug-mill  which  has  been  described  is  the  best  thing  that 
can  be  used  for  tempering  brick  or  terra-  cotta  clays ;  it  packs 
the  clay  very  closely,  and  the  ware  made  from  material  tem- 
pered in  this  manner  is  very  homogeneous. 

RING-PITS. 

The  next  manner  of  tempering  clay  is  by  the  ring-pits,  which 
usually  furnish  clay  for  six  gangs,  and  are  run  either  by  horse 
or  steam  power. 

These  pits  are  about  twenty  feet  in  diameter,  two  feet  in 
depth,  and  commonly  hold  clay  sufficient  to  make  fourteen 


MAKING   AND    BURNING    OF    HAND-MADE   BRICK.  109 

thousand  brick ;  they  are  cased  around  with  hard-burned  brick, 
and  the  bottom  is  usually  covered  with  oak  planks,  cut  wedge- 
shape.  Hard  pine  is  cheaper  than  oak,  and  is  also  used. 

There  is  a  pedestal  firmly  set  in  the  centre  of  the  pit,  upon' 
which  the  machinery  that  works  the  tempering  wheel  is  placed. 

For  a  ring-pit  worked  by  horses,  there  is  a  long  shaft  of  iron 
passing  through  the  centre  of  a  wheel,  about  six  feet  in  di- 
ameter, called  the  tempering-wheel,  and  terminating  beyond 
the  ring  far  enough  for  two  horses  to  be  hooked  to  it,  and  have 
room  sufficient  to  travel  around  the  ring  with  it. 

There  is  a  gearing  of  wheels  so  arranged  as  gradually  to 
push  the  tempering-wheel  from  the  centre  to  the  outer  edge  of 
the  pit,  while  the  wheel  is  revolving  around  the  circle,  and 
when  it  reaches  the  outer  edge  to  again  gradually  draw  it 
towards  the  centre. 

In  the  pits  using  horses  to  work  them,  there  is  sometimes  a 
small  wheel,  about  one  foot  and  six  inches  in  diameter,  and 
which  travels  in  a  level  track  around  the  edge  of  the  ring,  sup- 
porting the  long  iron  shaft  which  passes  through  it. 

Recent  changes  have  been  made^in  the  wheel  by  placing  the 
spokes  at  an  angle,  producing  a  dish  in  the  wheel,  so  as  to  suit 
the  circle  of  the  pit,  saving  the  labor  of  the  horses ;  it  also 
grinds  and  leaves  the  surface  of  the  clay  level  in  the  pit  during 
and  after  grinding.  An  illustration  of  the  Raymond  tempering- 
wheel,  made  by  C.  W.  Raymond  &  Co.,  Dayton,  Ohio,  is  shown 
in  Fig.  10.  The  capacity  of  tempering- wheels  of  course  de- 
pends upon  the  nature  of  the  clay  and  also  the  power  furnished  ; 
but  the  wheel  shown  in  Fig.  10  will  temper  clay  for  30,000  to 
40,000  brick  per  day  under  favorable  conditions.  The  open- 
tooth  and  the  box  racks  are  now  in  use ;  the  latter  have  the 
cogs  placed  on  the  inside  around  the  rack,  a  rib  on  the  top  side 
placed  lengthwise,  and  when  coming  in  contact  with  a  pin 
placed  in  the  bottom  side  of  the  cross-bar  on  the  saddle,  causes 
the  rack  to  shift.  The  racks  can  be  made  of  different  lengths, 
to  suit  smaller  sized  pits,  when  necessary.  Directions  can  be 
obtained  for  setting  the  wlieels  on  application  to  the  manu- 
facturers. 


110  BRICK,  TILES    AND   TERRA-COTTA. 

When  steam  is  the  motive  power,  the  principle  of  construc- 
tion is  about  the  same ;  but  the  shaft  which  passes  through  the 
tempering  wheel  does  not  extend  much  beyond  the  edge  of  the 
ring,  and  the  whole  machinery  is  attached  to  a  vertical  shaft, 
and  on  the  top  is  a  heavy  bevelled  gearing. 

FIG.  10. 


Serious  difficulties  have  been  encountered  in  constructing 
and  operating  machines  of  this  class,  from  the  fact  that  the 
power  which  has  propelled  them  has  been  communicated 
through  some  horizontal  shaft  above  the  receptacle  for  the 
material  to  be  tempered,  which  arrangement  has  necessitated 
the  use  of  a  long  vertical  shaft  to  communicate  the  motion  of 
such  horizontal  shaft  to  the  shaft  and  gear-wheels  which  propel 
the  tempering-wheel.  This  arrangement  of  the  parts  has  ren- 
dered necessary  expensive,  and  in  many  cases  inconvenient, 
frame-work  to  support  the  shafting,  which  often  interferes  with 
the  efficient  working  of  the  machine,  and  is  always  a  large  ad- 
dition to  its  cost.  Another,  and  a  very  serious  objection,  has 
arisen  from  the  fact  that  the  pinion  which  meshes  into  the 
circular  rack  upon  the  upper  surface  of  the  clay  receptacle  has 
been  constructed  in  accordance  with  well-known  rules  as  to  its 
diameter  and  the  pitch-line  of  its  teeth,  which  form  of  construc- 
tion, it  is  claimed,  is  found  defective  in  this  particular  case. 

When  steam  power  is  employed  for  driving  these  machines, 
two  of  the  pits  are  placed  on  the  same  line,  the  distance  be- 
tween the  nearest  points  of  the  circles  being  about  six  feet. 

There  are  no  separate  temperers  for  the  ring-pits  of  either 
class ;  the  driver  of  the  horses  in  one  case,  and  the  engineer  in 


MAKING    AND    BURNING   OF    HAND-MADE   BRICK.  I  I  I 

the  other,  let  the  water  into  the  clay,  and  see  that  it  is  properly 
tempered.  It  requires  two  of  these  pits,  of  either  class,  to 
temper  clay  for  six  gangs,  as  it  is  worked  out  of  one  pit,  while 
the  other  pit  of  clay  is  being  tempered.  The  sheds,  which 
must  be  maintained  over  the  ring-pits  of  both  classes,  are  much 
more  expensive  for  the  ones  that  are  run  by  steam  power  than 
for  the  other  class,  as  the  timbers  have  to  be  very  heavy,  and 
well  framed  and  braced.  Sometimes  clay  enough  to  make 
twenty-eight  thousand  brick,  which  is  sufficient  for  twelve  gangs, 
is  worked  out  of  two  ring-pits  daily ;  when  this  is  so,  the  pits 
are  filled  after  the  gangs  stop  work,  and  the  clay  is  then  tem- 
pered during  the  night  time. 

After  the  clay  is  tempered  in  ring-pits,  it  is  covered  with  large 
battened  panels,  made  of  light  pine  wood  nailed  together,  the 
object  being  to  keep  the  clay  moist,  and  prevent  it  from  drying 
on  the  top  before  it  is  used.  The  laborers  in  the  brick-yards 
like  the  clay  tempered  in  ring-pits,  as  they  can  go  in  separate 
gangs  at  any  time  and  commence  work  without  waiting  for  a 
complement  of  gangs,  which  has  to  be  done  when  pug-mills  are 
used  for  tempering. 

It  is  no  unusual  thing  for  brick-yard  gangs,  in  the  hot  season 
of  the  year,  to  commence  their  task  at  about  twelve  o'clock  at 
night,  when  the  moon  gives  sufficient  light,  and  have  their 
work  of  moulding  done  before  seven  o'clock  in  the  morning. 
Ring-pits  facilitate  this  more  than  does  any  other  mode  of 
tempering  the  clay. 

The  invention  of  Mr.  Henry  Aiken,  of  Philadelphia,  Pa.,  is 
shown  in  Figs,  n,  12,  13  and  14,  and  the  main  object  of  his 
invention  is  to  dispense  with  complex  driving-gearing,  and  to 
apply  the  power  more  advantageously  than  usual.  A  further 
object  is  also  to  simplify  the  devices  by  which  the  radial  move- 
ment of  the  tempering-wheel  on  its  shaft  is  effected,  and  to  so 
construct  the  same  that  a  vertical  movement  of  the  wheel  is 
allowed  without  danger  of  throwing  the  operating  mechanism 
out  of  gear.  These  objects  are  attained  in  the  manner  which 
we  will  now  proceed  to  describe,  reference  being  had  to  the 
drawings,  in  which — 


112  BRICK,  TILES    AND   TERRA-COTTA. 

Fig.  1 1  is  a  plan  view  of  a  clay-pit  with  Aiken's  improve- 
ments;  and  Figs.  12  and  13  and  14,  sections  on  the  lines  I  2, 
3,  4,  5,  6,  Fig.  il,  respectively. 

A  is  the  pit,  in  the  centre  of  which  is  a  vertical  standard,  a, 
and  to  the  top  of  the  latter  is  adapted  a  loose  sleeve,  x,  carry- 
ing two  pulleys,  b  and  d,  the  former  of  which  receives  power 
from  any  adjacent  shaft — for  instance,  that  shown  at  c — while 
the  pulley  d  transmits  this  power,  by  means  of  a  suitable  belt 
to  a  pulley,  e,  carried  by  a  vertical  shaft,  /,  adapted  to  bearings 

FIG.  ii. 


at  the  outer  end  of  the  radial  arm,  B,  the  inner  end  of  which 
turns  on  the  central  post  a.  From  the  outer  end  of  the  arm  B 
projects  a  short  shaft,  B\  carrying  a  loose  traction- wheel,  D, 
the  periphery  of  which  is  adapted  to  the  rim  of  the  pit  and  a 
worm-wheel,  gy  on  the  hub  of  the  traction-wheel,  gears  into  a 
worm,  hy  on  the  shaft  /.  (See  Fig.  12.)  For  the  sake  of 
economy,  it  is  preferable  to  make  the  wheel  D  comparatively 
light,  and  to  increase  its  traction  power  by  hanging  upon  the 
outer  end  of  its  shaft  a  box  of  clay  or  other  cheap  weight,  E. 
The  arm  B  is  connected  to  the  outer  end  of  the  shaft  F,  which 
carries  the  tempering-wheel  /,  by  means  of  the  link  i  and  rods 
j  /,  and  the  tempering-wheel  is  hung  to,  or  forms  part  of,  a 


MAKING   AND   BURNING   OF   HAND-MADE   BRICK.  113 

sleeve,  y,  so  adapted  to  the  shaft  F  that  it  can  be  moved  from 
or  towards  the  centre  of  the  pit,  this  movement  being  effected, 
as  usual,  by  means  of  the  double  rack  M  and  pinion  N,  the  di- 
rection of  the  movement  depending  upon  whether  the  upper  or 
lower  rack  is  in  gear  with  the  pinion.  Instead  of  rotating  the 
pinion  A^  from  a  central  shaft  by  means  of  spur-gearing,  as 
usual,  however,  it  is  secured  to  one  end  of  a  spindle,  m,  adapted 
to  bearings  at  the  inner  end  of  the  arm  B,  and  carrying,  near 
its  opposite  end,  a  worm-wheel,  P,  the  teeth  of  which  engage 
with  a  worm,  S,  secured  to  the  stem  a.  (See  Fig.  13  and 
dotted  lines,  Fig.  14.) 


FIG.  13. 


FIG.  12. 


FIG.  14. 

When  power  is  applied  to  the  shaft /at  the  outer  end  of  the 
arm  B,  the  traction-wheel  D  is  caused  to  revolve,  and  travels 
around  the  rim  of  the  pit,  carrying  with~it]the  arm  By  and  con- 
sequently the  shaft  F  and  tempering-wheel  /,  while  at  the  same 
time  the  movement  of  the  worm-wheel  P  around  the  worm  5  on 
the  central  stem  a  causes  the  rotation  of  said  worm-wheel  and 
the  operation  of  the  mechanism  which  effects  the  radial  move- 
ment of  the  tempering-wheel. 

It  will  be  evident  that  by  the  above-described  arrangement 
the  power  required  to  effect  the  movement  of  the  tempering- 
wheel  is  applied  more  directly,  and  with  less  loss  by  friction, 
than  when  this  power  is  applied  to  the  inner  end  of  the  temper- 
ing-wheel arm  by  means  of  gearing  from  a  central  rotating 


114  BRICK,  TILES    AND    TERRA-COTTA. 

shaft,  while  the  use  of  the  simple  traction-wheel  D  at  the  edge 
of  the  pit  obviates  the  necessity  of  locating  costly  and  incon- 
venient mechanism  at  this  point. 

By  the  use  of  the  fixed  worm  S  on  the  stem  tf,  and  the  worm- 
wheel  P  carried  by  the  arm  B,  the  said  wheel  P  can  be  caused 
to  revolve  at  the  required  speed  without  the  intervention  of  the 
usual  system  of  gearing,  which  is  complicated  and  expensive, 
and  causes  loss  of  power  by  friction. 

It  will  be  observed  in  Figs,  n,  13  and  14  that  the  inner  end 
of  the  shaft  F  is  pivoted  to  the  shaft  m,  which  carries  the  pinion 
N  for  operating  the  rack  M,  so  that  when  the  tempering-wheel 
rises  or  falls,  owing  to  inequalities  in  the  bottom  of  the  pit,  the 
centre  of  movemnnt  will  be  at  the  shaft  m,  thus  preventing  the 
risk  of  throwing  the  rack  out  of  gear  with  the  pinion,  which 
this  movement  causes  in  machines  of  this  class  as  usually  con- 
structed. 


CHAPTER  IV. 

THE  MANUFACTURE   OF   TEMPERED-CLAY  BRICK ;    INCLUDING  A 
DESCRIPTION  OF  THE  MOST  MODERN  MACHINERY  EMPLOYED. 

GENERAL    REMARKS. 

THE  enormous  demand  for  brick  in  the  large  cities  of  the 
United  States  has  vastly  stimulated  the  invention  of  all  classes 
of  machinery  to  save  labor  and  to  produce  quickly  large  quanti- 
ties of  green  brick  from  crude  clay. 

The  proper  selection  of  clays  as  regards  quantity  and  quality, 
and  the  suitable  location,  construction  and  economical  arrange- 
ment of  a  brick-making  plant,  coupled  with  a  practical  knowl- 
edge of  the  art,  are  the  corner-stones  of  financial  success  in  the 
business  of  brick-making. 

Cheap  transportation  of  the  machinery,  building  materials, 
and  of  fuel  to  the  place  of  manufacture,  and  of  the  brick  pro- 
duced, to  a  profitable  market,  is  necessary,  and  the  question  of 
the  existence  or  non-existence  of  such  facility,  either  by  cart- 
load, by  water  or  by  steam,  should  be  thoroughly  and  minutely 
examined. 

After  many  plants  for  the  manufacture  of  brick  have  been 
established  and  the  brick  made  and  burned,  the  question  un- 
fortunately is  only  too  often  asked :  "  Have  I  a  suitable  market 
for  the  brick  which  I  make  now  and  propose  to  make  in  the 
future?"  Whether  or  not  you  have  a  sufficient  market  depends 
to  some  extent  upon  the  kind  of  brick  proposed  to  be  manu- 
factured. 

If  it  is  proposed  to  make  common  building  brick  entirely,  it 
will  be  necessary  to  depend  upon  home  consumption ;  i.  e.,  the 
brick  must  be  sold  to  be  used  in  the  vicinity  of  where  they  are 
produced.  With  few  exceptions,  common  brick  cannot  be 

("5) 


Il6  BRICK,  TILES   AND   TERRA-COTTA. 

shipped  a  great  distance  with  profit,  as  the  freight  on  a  thous- 
and common  brick  is  entirely  out  of  proportion  to  the  amount 
of  money  they  represent  in  profits ;  and  then,  too,  clays  for 
common  building  brick  can  usually  be  found  in  abundance 
near  the  locality  where  the  brick  are  to  be  used,  so  that  the 
difference  in  transportation  alone  may  be  sufficient  in  amount 
to  more  than  overbalance  a  good  profit. 

When  pressed,  ornamental,  enameled  and  the  finer  classes  of 
brick  are  to  be  the  principal  output  of  the  works,  the  item  of 
transportation  is  not  such  an  important  feature,  for  the  reason 
that  the  freight  is  not  out  of  proportion  to  the  value  of  the 
product. 

These  facts  aid  in  making  for  the  pressed-brick  manufacturer 
a  market  extended  over  a  much  greater  extent  of  territory  than 
is  possible  for  the  maker  of  common  brick. 

A  manufacturer  may  make  a  good  quality  of  brick,  and  with 
economy,  and  fail  for  the  simple  reason  that  the  market  at 
command  cannot  sustain  the  output  from  his  yard,  or  from 
yards  in  his  vicinity. 

This  has  been  unfortunately  demonstrated  in  both  the  brick 
and  drain  tile  business,  especially  in  Indiana  and  Illinois. 

The  recent  rapid  progress  in  the  art  of  brick  manufacturing 
has  not  been  accomplished  without  great  loss  of  money  to  the 
pioneers  in  the  movement,  and  many  distressing  perplexities. 

The  transitions  from  the  old  and  obsolete  method  have  given 
way  to  the  modern  brick -making  machinery.  To  adapt  appli- 
ances to  work  the  different  clays  has  been  a  most  costly  and 
harassing  experiment;  but  at  last  perseverance  and  patience 
have  triumphed,  and  the  business  of  brick-making  has  reached 
a  safe  and  reliable  basis  as  regards  machinery.  It  has  nearly 
reached  perfection  in  the  economical  manner  of  tempering  clay 
and  forming  the  brick.  The  tempering  wheel  has  almost  dis- 
appeared, and  in  its  stead  are  a  number  of  good  grinders  or 
disintegrators  which  give  satisfaction. 

The  different  kinds  of  brick  machines  may  be  classed  under 
three  heads,  viz. :  1st,  the  soft  mud  ;  2d,  the  dry-press  ;  and  3d, 


MANUFACTURE  OF  TEMPERED-CLAY  BRICK.      117 

the  stiff-mud  or  wire-cut.  Each  of  them  has  its  adherents,  and 
each  has  its  good  and  bad  qualities,  and  each  is  best  adapted 
to  different  clays  in  different  localities. 

Probably  the  three  most  serious  drawbacks  in  modern  ma- 
chinery will  be  :  First,  a  tendency  to  over-production.  Second, 
the  tendency  to  make  machine-made  bricks  too  large,  which 
greatly  increases  the  cost  of  manufacture.  A  suitable  and 
proper  size  for  brick  is  2^  inches  thick,  4^{  inches  wide,  8^ 
inches  long.  Third,  the  inducements  which  machinery  offers 
to  inexperienced  beginners  who  engage  in  the  business  and 
make  a  poor  quality  of  brick,  and  consequently  reduce  the 
price. 

It  is  not  the  purpose  of  this  work  to  canvass  and  give  the 
merits  or  demerits  of  any  particular  machine ;  but  by  saying 
what  has  just  preceded,  merely  to  hint  at  a  few  of  the  consider- 
ations which  should  govern  those  who  part  with  their  money 
for  the  purchase  of  either  the  stock  produced,  or  for  a  machine 
itself. 

The  process  of  manufacturing  brick  by  machinery  may  be 
divided  into  five  stages,  viz. : 

Mining,  tempering  and  preparation  of  the  clay. 

Shaping  the  brick. 

Drying. 

Setting. 

Burning. 

Having  described  the  manufacture  of  dry-clay  brick  and 
street-paving  brick  in  separate  chapters,  those  systems  will  be 
touched  upon  in  the  present  one  only  so  far  as  may  be  neces- 
sary to  illustrate  some  specific  point. 

MINING  CLAY  FOR  BUILDING-BRICK. 

One  of  the  great  difficulties  usually  encountered  by  the  man- 
ufacturers of  building-brick  who  have  established  extensive 
works  near  large  bodies  of  clay  is  to  get  sufficient  clay  dug, 
loaded,  and  elevated  to  meet  the  demand  for  the  material. 
Along  the  banks  of  the  Ohio  River  where  the  brick  clay  ranges 


n8 


BRICK,  TILES    AND   TERRA-COTTA. 


from  25  feet  to  35  feet  in  depth,  and  which  clay  is  of  a  tough 
and  lumpy  nature,  and  often  runs  into  the  wet-stirT-blue  clay,  it 
is  hard  to  obtain,  except  at  large  expense,  laborers  to  dig, 
cave,  and  shovel  the  material. 

By  this  method  the  cost  of  placing  the  clay  in  the  tempering 
shed  averages  fifty  cents  per  thousand  in  the  locality  named, 
and  as  there  is  no  certainty  of  a  full  supply  of  clay  for  each 
day's  work,  the  result  is  short  time  and  no  assurance  of  any 
regular  output  of  brick. 

Men  in  caving  are  often  caught  in  the  falling  bank  and  be- 

FIG.  15. 


come  disabled,  and  it  makes  them  wary  of  undertaking  the 
"job"  again,  and  consequently  it  becomes  extremely  hard  to 
employ  labor  for  that  class  of  work. 

There  are  a  large  number  of  mechanical  clay-diggers  now 
manufactured  and  designed  to  perform  the  work  described,  but 
the  Barnhart  steam  shovel,  shown  in  Fig.  1 5,  will  dig  clay  enough 
for  from  150,000  to  200,000  brick  daily,  and  by  its  use  moder- 
ate-sized yards  can  enlarge  their  capacity  as  desired. 

The  steam  shovel  shown  in  Fig.  1 5  is  built  by  the  Marion 
Steam  Shovel  Company,  Marion,  Ohio,  and  the  machine  is  self- 


MANUFACTURE    OF   TEMPERED-CLAY   BRICK.  119 

propelling  and  cuts  the  clay  to  a  height  of  18  feet,  and  will  load 
300  to  400  cubic  yards  per  day.  It  digs  the  clay  from  top  to 
bottom  of  bank,  thoroughly  mixing  it.  It  is  built  on  a  solid 
frame-work  upon  standard  gauge-wheels,  and  can  be  moved  any 
distance  backward  or  forward  simply  by  laying  a  track.  At 
night  it  can  be  locked  up  securely  from  intrusion  by  meddlers, 
as  it  has  a  substantial  cab  built  over  it.  It  is  the  cheapest, 
best,  and  simplest  machine  we  know  for  the  purpose,  and  gives 
entire  satisfaction.  It  is  operated  by  an  engineer,  one  crane 
boy  and  an  outside  man.  Formerly  it  took  eight  men  to  do 
this  work.  These  diggers  hardly  pay  on  works  making  less 
than  50,000  brick  per  day.  A  smaller  and  less  costly  steam 
shovel  would  dig  the  clay  for  50,000  brick  daily,  if  properly 
constructed  and  the  clay  to  be  dug  is  not  too  tough. 

The  Purington-Kimball  Brick  Co.,  of  Chicago,  111.,  has  sub- 
stituted electric  power  for  steam  in  operating  steam-shovels 
used  for  the  digging  of  clay,  owing  to  the  difficulty  experienced 
in  getting  coal  to  the  shovel. 

Manufacturers  of  brick  whose  plants  are  located  in  the  cen- 
tral or  elevated  portions  of  the  country,  can  readily  appreciate 
the  advantage  in  digging  clay,  which  others  have  who  possess 
inexhaustible  banks  of  clay  near  at  hand. 

Some  manufacturers  in  the  interior  of  the  country  have  to 
haul  their  clay  half  a  mile  or  a  longer  distance,  and  in  some 
cases  eighteen  inches  to  two  feet  is  the  maximum  depth.  Even 
scrapers  and  ploughs  in  such  instances  are  impracticable,  and 
the  only  way  to  dig  such  clay  is  to  turn  it  over,  let  the  weather 
slack  it,  and  by  muscle  and  good  strong  horses  and  carts  move 
it  away.  It  takes  sixty-four  cubic  feet  of  clay  to  make  a  thous- 
and brick,  and  a  cart  having  a  haul  of  one-half  mile  makes 
about  twelve  loads  for  a  day's  work,  and  this  seems  to  be  the 
most  advantageous  method  of  moving  clay  that  distance. 

Manufacturers  of  brick  having  banks  of  clay  eight  or  ten  feet 
in  depth  often  plow  the  clay  when  they  have  satisfactory  ar- 
rangements for  mixing  it ;  but  when  the  clay  cannot  be  properly 
mixed  it  is  better  to  "  fall "  the  bank,  and  in  that  way  mix  the 


120  BRICK,  TILES   AND   TERRA-COTTA. 

top  and  the  bottom  and  the  strong  and  the  weak  clay.  Where 
fifty  thousand  brick  are  made  per  day,  and  the  clay  is  only  two 
or  three  hundred  yards  away,  five  men  and  three  horses  and 
carts  should  be  sufficient  to  move  the  clay  to  the  crushers  or 
pulverizers. 

WINDING   DRUMS    AND    DUMP    CARS. 

As  steam  has  taken  the  heavy  work  of  transporting  the  pro- 
ducts of  the  country  from  the  horses  which  formerly  did  the 
overland  hauling,  so  it  is  doing  now  in  the  brick  and  tile  fac- 
tories. 

The  apparatus  for  drawing  the  clay  into  the  factory  by  the 
engine,  being  in  the  first  place  cheaper  than  horses  and  carts 
and  doing  the  work  without  a  driver,  besides  not  being  at  ex- 
pense when  idle,  it  was  a  natural  result  that  the  winding  drum 
and  automatic  dump  cars  were  adopted  by  all  enterprising 
brick  manufacturers. 

To  suit  different  demands,  the  Frey-Sheckler  Co.,  of  Bucyrus, 
Ohio,  has  constructed  two  styles  of  winding  drums,  which  are 
self-contained  in  substantial  iron  frames,  and  can  be  operated 
by  a  cord  from  the  clay  pit  or  by  the  engineer  from  any  point 
in  the  factory. 

Fig.  1 6  illustrates  the  Friction  Winding  Drum  which  the 
Frey-Sheckler  Co.  make  in  three  sizes,  to  wit:  Nos.  I,  2  and 
5.  A  machine  of  this  kind  is  one  of  the  essentials  of  a  well 
equipped  brick  factory,  for  the  transportation  of  clay  from  the 
pit  to  the  factory.  This  Drum  is  substantially  built.  The  frame 
is  heavy,  and  is  so  constructed  that  it  can  be  bolted  to  the 
upper  part  of  the  track  timber. 

No.  I  Drum  has  a  friction  pulley  40  inches  diameter  and  7- 
inch  face.  The  paper  friction  pulley  is  8  inches  diameter  and 
7  inch  face.  The  driving  pulley  is  24  inches  diameter  and  6- 
inch  face.  Speed,  500  revolutions  per  minute ;  geared  5  to  I  ; 
weight  of  Drum  without  cable,  1,100  pounds.  Drum  will  hold 
800  feet  ^-inch  iron  cable. 

No.  2  Drum  has  a  friction  pulley  30  inches   diameter  and 


MANUFACTURE   OF  TEMPERED-CLAY    BRICK. 


121 


6  inch  face.  The  paper  friction  pulley  is  6  inches  diameter  and 
6  inch  face.  The  driving  pulley  is  26  inches  in  diameter  and 
6  inch  face.  Speed,  500  revolutions  per  minute ;  geared  5  to 
i  ;  weight  of  Drum  without  cable,  700  pounds.  Drum  will 
hold  300  feet  ^-inch  iron  cable. 

No.  5  Drum  is  24  inches  diameter  and  36  inches  long  inside 
of  flanges,  which  are  5  inches  high  all  around.  Diameter  of 
main  shaft,  3^  inches;  diameter  of  pulley  shaft,  2 ^  inches. 
Speed,  350  revolutions  per  minute;  geared  5  to  I.  Driving 

FIG.  i 6. 


FRICTION    WINDING    DRUM. 


pulley  is  24  inches  diameter,  10  inch  face.  This  drum  will 
hold  3,400  feet  of  ^-inch  cable.  Weight  of  drum  without 
cable,  4,500  pounds.  Floor  space  required,  7  feet  by  5  feet  9 
inches. 

Fig.  17  illustrates  the  gear  and  friction  winding  drum  made 
by  the  Frey-Sheckler  Co.,  which  is  made  in  two  sizes,  to-wit: 
Nos.  3  and  4.  The  construction  throughout  is  strong,  simple 
and  durable.  It  is  not  liable  to  breakage  or  derangement,  and 
is  mounted  on  a  solid  white  oak  frame.  The  drum  runs  loose 
on  the  shaft  and  engages  itself  with  the  wood  friction  (which 
is  securely  bolted  to  the  large  spur  gear)  by  being  forced 
along  the  shaft  by  means  of  the  lever. 

This  lever  is  connected  by  a  rod  with  the  band  brake  lever, 


122 


BRICK,  TILES    AND   TERRA-COTTA. 


so  that  both  the  friction  and  the  brake  levers  are  operated  by 
one  movement.  Thus  with  the  levers  in  a  central  position,  as 
shown  in  the  engraving,  the  drum  is  left  free  to  revolve  on  the 
shaft.  When  the  levers  are  forced  down  the  brake  is  applied, 
and  holds  the  drum  or  lowers  the  load  as  desired.  When  the 
levers  are  raised  the  drum  is  brought  into  contact  with  the 
friction  disc  and  raises  the  load,  then  the  brake  is  released. 
This  brings  it  fully  under  the  control  of  the  operator. 

No.  3  Drum  is  12  inches  in  diameter  and  24  inches  long  in- 
side of  the  flanges,  which  are  5   inches  high  all  around.     The 

FIG.  17. 


GEAR  AND  FRICTION  WINDING  DRUM. 


driving  pulley  is  24  inches  diameter,  8  inch  face.  Speed,  550 
revolutions  per  minute;  geared  4^  to  I.  This  drum  will  hold 
1,300  feet  of  5/g  inch  cable.  Weight  of  drum  without  cable, 
1,725  pounds. 

No.  4  Drum  is  24  inches  in  diameter  and  30  inches  long  in- 
side of  flanges,  which  are  5  inches  high  all  around.  Geared  5 
to  i.  Diameter  of  main  shaft  3^  inches,  diameter  of  pulley 
shaft  2^  inches.  Speed,  350  revolutions  per  minute.  Driving 
pulley  is  24  inches  diameter,  8  inch  face.  This  drum  will  hold 


MANUFACTURE   OF   TEMPERED-CLAY    BRICK. 


123 


2,800  feet  $/%  inch  cable.  Weight  of  drum  without  cable,  3,500 
pounds.  Floor  space  required,  6  feet  7  inches  by  5  feet  8 
inches. 

The  speed  of  the  above  drums  was  based  upon  the  supposi- 
tion that  the  dump  car  travels  six  miles  per  hour. 

Fig.  1 8  illustrates  the  Side  Dumping  Clay  Car,  made  by  the 

FIG.  i 8. 


Frey-Sheckler  Co.  This  car  is  substantially  constructed  in 
all  parts ;  it  is  made  to  dump  on  one  side  only,  but  it  can 
be  furnished  to  dump  on  both  sides  if  desired.  The  side  is 
hinged  from  the  top  and  arranged  so  that  when  the  car  is 
tilted  over  the  catch  holding  the  car  in  position  is  released, 
allowing  the  side  to  swing  out  at  the  bottom.  The  wheels,  17 


I24 


BRICK,  TILES    AND   TERRA-COTTA. 


inches  in  diameter,  are  very  heavy,  chilled  and  annealed.  This 
car  is  made  in  three  sizes.  No.  3,  capacity  j{  cubic  yard,  track 
gauge,  36  inches ;  No.  4,  i  cubic  yard,  track  gauge,  36  inches ; 
No.  5,  \y2  cubic  yards,  track  gauge,  42  inches. 

Fig.  19  illustrates  the  Bottom  Dumping  Clay  Car,  manu- 
factured by  the  Frey-Sheckler  Co.  This  car  is  remarkably 
strong.  The  timbers  are  heavy  and  securely  bolted  together; 

FIG.  19. 


the  wheels,  17  inches  in  diameter,  are  thoroughly  chilled  and 
annealed,  and  the  workmanship  throughout  equal  to  the  high- 
est established  standard.  This  car  is  arranged  to  dump  auto- 
matically. The  bottom  is  in  two  parts  and  hinged  at  the 
sides  of  the  box,  and  held  in  position  by  two  chains  which  are 
attached  to  an  arm  keyed  to  a  steel  cross-shaft  which  has  a 
lever  on  the  outside  of  the  car,  which  is  held  in  position  by  a 
catch  that  hangs  down  between  the  wheels  near  the  track.  A 
stop  fastened  to  the  track  releases  this  catch  and  lets  the  bottom 


MANUFACTURE    OF   TEMBERED-CLAY   BRICK.  125 

drop,  when  the  car  runs  back,  and  the  diggers,  by  a  pull  of  the 
lever,  again  place  the  bottom  in  position.  The  Frey-Sheckler 
Company  make  two  sizes  of  this  style  of  car.  No.  I,  capacity 
y^  cubic  yard,  track  gauge,  42  inches;  No.  2,  capacity  I  cubic 
yard,  track  gauge,  42  inches. 

TEMPERING   AND    PREPARING    CLAY. 

In  early  days,  for  tempering  clay  men  first  spaded  and  then 
stamped  it  with  their  feet ;  next  oxen  trod,  afterward  the  gum, 
later  horses  and  wheel,  finally  the  steam  wheel  took  the  place 
of  horses  for  tempering  the  clay.  Then  in  turn  the  steam 
wheel  had  to  go,  and  in  its  stead  we  had  rollers  to  break  the 
lumpy  clay,  and  now  disintegrators  and  grinders  to  thoroughly 
pulverize  it  are  employed. 

The  clay-crushers  that  are  now  being  used  commonly  have 
smooth  rollers,  although  almost  every  one  of  them  has  some 
device  for  tearing  the  clay  to  pieces.  The  inventors  of  brick- 
making  machines  have  learned  that  something  must  be  done  in 
the  way  of  preparing  the  clay  other  than  by  smooth  rolling. 
The  day  is  not  far  distant  when  it  will  be  a  necessity  to  put 
more  expensive,  stronger  and  better  machinery  into  preparing 
clay  than  has  yet  been  done :  some  device  which  will  thor- 
oughly pull  the  clay  apart  and  open  the  pores. 

In  order  to  make  a  good  brick,  either  soft-mud,  dry-pressed, 
semi-dry,  stiff-mud,  hand-made,  or  any  other  kind  of  brick,  the 
clay  should  be  properly  prepared.  It  should  be  ground  very 
fine,  whether  it  be  ground  first,  dried,  and  then  tempered  with 
water,  or  whether  it  be  ground  with  the  water ;  the  finer  the 
clay  is  ground  the  better  the  brick  will  be.  In  the  majority  of 
cases  where  dry-clay  brick  have  been  found  to  be  a  failure,  one 
of  the  reasons  for  the  lack  of  success  in  their  manufacture  will 
be  found  to  be  because  the  clay  was  not  properly  ground. 

If  a  good  hand-made  brick  is  desired,  prepare  the  clay,  make 
it  smooth,  work  the  clay  thoroughly,  and  let  the  proprietor  see 
for  himself  that  it  is  prepared.  In  clays  not  ground  properly, 
dry  lumps  of  clay  in  the  brick  cause  it  to  break  and  burst.  This 
is  proof  that  the  clay  must  be  properly  prepared. 


126  BRICK,  TILES   AND   TERRA-COTTA. 

It  is  better  to  take  the  clay  out  in  the  fall,  and  let  it  be  ex- 
posed to  rain  and  frost  during  the  winter.  By  so  doing  it  is 
possible  to  burn  brick  15  or  20  cents  per  thousand  cheaper 
than  if  the  clay  is  taken  fresh  from  the  bank ;  that  is,  by  the 
old  way  of  burning. 

A  machine  which  is  going  out  of  date,  because  it  has  been 
superseded  by  the  modern  pug-mill,  is  the  old-fashioned  tem- 
pering wheel. 

There  has  probably  never  been  a  tempering  device  by  which 
clay  could  be  prepared  so  evenly,  uniformly,  and  thoroughly, 
and  as  perfectly  in  every  respect,  as  with  the  tempering  wheel ; 
but  it  costs  so  much  more  to  temper  clay  with  the  wheel  than 
by  the  pug-mill  that  the  tempering  wheel  must  soon  disappear 
because  it  costs  too  much  to  prepare  the  clay  with  it. 

Where  there  are  different  strata  of  clay  to  be  worked,  soak 
pits  should  be  used  in  which  to  thoroughly  mix  the  clays. 

If  there  are  made  as  many  as  35,000  brick  per  day  in  a  yard, 
the  soak  pits  should  be  about  35  feet  long,  12  feet  wide,  and  4 
feet  deep :  put  an  elevator  right  in  the  centre  of  the  pit,  run  a 
chain  belt  from  the  lower  end  of  the  pit,  bringing  it  up  on  an 
incline,  which  will  allow-the  clay  to  be  drawn  up  into  the  ma- 
chine. If  the  clay  is  of  a  greasy  character,  have  a  little  water 
running  which  will  aid  to  slide  up  the  incline.  There  should  be 
no  trouble  in  carrying  up  clays  in  that  way  when  the  clay  is 
soaked  before  it  is  put  into  the  machine. 

In  making  tiles  or  fine  brick,  soaking  the  clay  a  few  days 
before  using  it  pays,  and  it  is  necessary,  in  order  to  have  brick 
with  lasting  qualities,  that  the  material  should  be  made  thor- 
oughly homogeneous  before  it  is  moulded. 

When  the  clay  to  be  employed  is  of  the  bluish  variety, 
lumpy,  rough  and  difficult  to  soak,  it  will  pay  to  use  a  crusher, 
as  otherwise  the  bricks,  although  strong,  will  be  rough  in  ap- 
pearance and  often  not  marketable. 

In  clays  where  rock  or  pebbles  are  present  or  where  the  clay 
has  not  been  thoroughly  disintegrated  by  frost  and  exposure, 
we  do  not  know  of  any  better  remedy  than  the  use  of  the  disin- 
tegrator, and  our  experience  is  decidedly  in  its  favor. 


MANUFACTURE   OF   TEMPERED-CLAY   BRICK.  127 

The  plan  is  sometimes  adopted  to  temper  clay  by  conveying 
it  to  a  horizontal  clay  mill,  into  which  it  is  fed  as  evenly  as  pos- 
sible with  a  spray  of  water  thrown  on  it,  regulated  to  any  de- 
sired quantity  by  a  stop-cock  under  control  of  the  feeder. 

The  clay  after  leaving  the  horizontal  conveyor  is  next  carried 
to  the  tempering  cylinder  of  the  brick  machine  and  there  re- 
ceives its  second  and  usual  pugging.  , 

This  process  does  very  well  for  the  early  spring  months ;  but 
as  the  season  advances  and  the  ground  becomes  drier,  many 
little  hard  lumps  pass  through  the  pug-mills  without  being 
crushed,  and  all  bricks  containing  them  crack  in  drying. 

The  experiment  has  been  tried  of  first  passing  the  clay  be- 
tween crushing-rolls,  but  the  clay  either  came  through  in  sheets 
which  were  hard  and  smooth  and  would  not  temper  in  the  pug- 
mills,  or  else  would  adhere  to  the  rolls  and  give  continued 
trouble  to  clean  them ;  and  the  only  satisfactory  solution  was  to 
use  a  disintegrator  and  pass  the  clay  through  it  before  convey- 
ing it  to  the  brick  machine. 

Hot  water  tempering  is  not  always  an  improvement  over  cold 
water,  as  it  often  makes  some  clays  more  sticky  and  difficult  to 
dump  from  the  moulds.  Hot  water  does  not  hasten  the  drying 
of  brick.  After  a  number  of  experiments,  in  which  brick  made 
by  each  process  were  placed  side  by  side,  the  difference,  if  any, 
was  too  small  to  compensate  for  the  disadvantage  of  sticky 
moulds. 

It  is  often  difficult  during  the  winter  months  to  reduce  hard- 
frozen  clay  to  that  condition  necessary  to  make  brick,  as  it 
clogs  in  the  rolls  or  pulverizer  and  causes  loss  of  both  time  and 
patience.  A  simple  method  for  thawing  clay  consists,  for  small 
works,  in  laying  down  a  plank  floor  about  8  feet  wide  by  20  feet 
long,  with  one  end  of  the  floor  a  few  inches  lower  than  the 
other.  Then  put  about  four  rows  of  one-inch  pipe  the  full 
length  of  this  floor,  and  far  enough  apart  to  shovel  between 
them  easily.  In  these  pipes,  about  one  foot  apart,  drill  holes 
about  one-sixteenth  of  an  inch  in  diameter,  on  alternate  sides, 
so  as  to  allow  an  emission  of  a  jet  of  steam  every  twelve  inches, 


128  BRICK,  TILES    AND   TERRA-COTTA. 

first  on  one  side  and  then  on  the  other.  Connect  the  pipes  at 
the  highest  end  of  the  floor  by  a  header,  and  place  a  plug  in 
each  pipe  at  the  lower  end,  with  a  small  hole  in  each  plug  to 
carry  off  the  drip  or  condensed  steam.  Lastly,  drive  some 
staples  down  over  the  pipes  to  keep  them  in  place,  and  then 
cover  the  pipes  over  with  about  30  tons  of  clay,  piled  six  feet 
high,  fill  the  boiler  well  up  with  water,  run  the  steam  down  to 
about  30  pounds  pressure,  turn  the  valve  connecting  the  boiler 
with  the  clay  pile  about  two  turns,  and  leave  it  in  that  condi- 
tion during  the  night.  The  next  morning,  under  an  outside 
crust  of  about  one  inch  thick,  will  be  found  the  clay  in  good 
condition  for  use  and  the  frost  out  of  it. 

The  simplicity,  cheapness,  and  complete  success  of  this  plan 
make  it  within  the  reach  of  all  clay-workers  who  have  steam  at 
command. 

A  great  deal  of  trouble  occurs  often  in  elevating  the  clay  to 
the  disintegrator,  or  from  the  disintegrator  to  the  brick  machine, 
especially  when  the  clay  is  a  little  wet,  as  it  sticks  fast  and  clogs 
on  the  belts  ;  and  oftentimes  this  trouble  can  be  greatly  lessened 
by  using  a  canvas  belt,  with  two  chains  on  sprocket  wheels,  at 
the  crusher  and  at  the  mill,  using  four-inch  rollers  about  a  foot 
apart  to  support  the  intervening  space.  One  of  the  greatest 
causes  of  failure  in  using  belt-elevators  is  having  them  too  steep 
and  not  properly  supported. 

Fig.  20  illustrates  the  No.  I  Granulating  Pug-Mill  built  by 
the  Frey-Sheckler  Co.  This  machine  is  built  very  heavy,  and 
is  10  feet  long  in  the  pugging  chamber,  which  is  made  of 
boiler  steel  J^  inch  in  thickness.  The  shaft  is  hammered  steel 
4^  inches  square.  The  knives  are  made  of  charcoal  chilled 
iron.  This  machine  is  used  for  granulating  tough,  strong 
clays  before  passing  to  a  crusher ;  this  is  a  very  essential 
feature  in  clays  of  this  character.  Inasmuch  as  the  stones  are 
liable  to  catch  on  the  knives  and  break  them,  a  safety  pin  is 
inserted  in  the  driving  pinion  so  as  to  prevent  breakages.  It 
also  acts  as  a  distributor  or  feeder  for  the  crusher. 

The  clay  is  dumped  in  at  the  rear  end  by  carts  or  dump  cars, 


MANUFACTURE   OF  TEMPERED-CLAY   BRICK. 


129 


130  BRICK,  TILES   AND   TERRA-COTTA. 

and  the  knives  tear  the  clay  to  pieces  and  gradually  carry  it 
along  while  disintegrating  it,  so  that  a  constant  and  even  stream 
flows  into  the  crusher,  and  the  rolls  take  it  through  readily. 
This  machine  is  provided  with  a  friction  clutch  pulley  36  inches 
in  diameter,  10  inch  face.  Speed,  150  revolutions  per  minute; 
weight,  7,000  pounds. 

CLAY    CRUSHERS. 

Fig.  21  illustrates  the  No.  I  Two  Roll  Crusher  built  by  the 
Frey-Sheckler  Co.,  which  is  made  for  exceedingly  stony 
clays.  The  frame  is  cast  in  one  piece  and  the  boxes  have 
heavy  rubber  springs  behind  them.  The  rollers,  16  inches 
diameter  and  24  inches  long,  are  made  of  charcoal  chilled 
iron  with  a  3-inch  steel  shaft  through  them.  The  steel  scrap- 
ers are  placed  on  lugs  with  slots  in  them,  so  that  they  can 
be  easily  adjusted  to  the  face  of  the  roll  as  the  edge  wears  off. 
This  is  a  very  strong  and  durable  crusher,  and  is  a  desirable 
substitute  in  places  where  other  crushers  failed,  owing  to  weak- 
ness in  construction.  This  machine  is  provided  with  a  patent 
friction  clutch  pulley.  Diameter  of  driving  pulley,  36  inches  ; 
face  of  driving  pulley,  10  inches ;  speed,  200  revolutions  per 
minute;  weight,  2,700  pounds. 

Fig.  22  illustrates  the  Four  Roller  Crusher  built  by  the  Frey- 
Sheckler  Co.,  and  which  is  made  in  two  sizes,  viz. :  Nos.  7 
and  8.  This  machine  is  very  heavy,  strong  and  durable,  and 
designed  for  use  in  brick  factories  where  large  capacity  is  re- 
quired. 

The  rolls  are  made  of  the  best  charcoal  chilled  iron,  mounted 
on  a  frame  of  wrought  iron  6  inches  wide,  I  ^  inches  thick ; 
each  pair  of  rolls  is  driven  by  independent  belts.  The  driven 
rolls  of  each  pair  are  provided  with  sliding  journal  boxes,  which 
are  backed  up  by  heavy  steel  coil  springs.  By  the  use  of  the 
sliding  boxes,  the  rolls  can  be  adjusted  as  may  be  desired. 

In  order  to  suit  the  great  variety  of  material  to  be  crushed, 
the  Frey-Sheckler  Co.  manufacture  three  styles  of  rolls  to  be 
used  for  the  upper  pair.  For  very  lumpy  and  stony  clays, 


MANUFACTURE   OF   TEMPERED-CLAY   BRICK, 


132 


BRICK,  TILES   AND   TERRA-COTTA. 


/ 


MANUFACTURE   OF   TEM-PERED-CLAY   BRICK.  133 

either  the  patent  stone  separating  or  conical  rolls  are  used,  and 
for  clays  of  alluvial  nature  smooth-face  rolls  are  employed.  The 
rolls  are  keyed  on  the  shaft  and  are  perfectly  balanced.  The 
rolls  are  supplied  with  adjustable  scrapers  made  of  tool  steel, 
which  keep  the  rolls  perfectly  clean. 

Number  7  Crusher  has  rolls  16  inches  diameter,  24  inches 
long;  driving  pulleys  36  inches  diameter,  10  inch  face.  Speed 
of  upper  rolls,  250  revolutions  per  minute  ;  speed  of  lower  rolls, 
275  revolutions  per  minute;  weight,  5,800  pounds. 

Number  8  Crusher  is  supplied  with  rolls  20  inches  diameter, 
26  inches  long;  driving  pulleys  36  inches  diameter,  10  inch 
face.  Speed  of  upper  rolls,  300  revolutions  per  minute;  speed 
of  lower  rolls,  325  revolutions  per  minute  ;  weight, 9,400  pounds. 

Both  of  these  Crushers  are  now  supplied  with  friction  clutch 
pulleys,  instead  of  plain  pulleys,  as  shown  in  the  cut. 

PUG-MILLS. 

Fig.  23  illustrates  the  No.  2  Pug-mill  built  by  the  Frey- 
Sheckler  Co.  This  pug-mill  has  a  shell  made  of  J^-inch 
boiler  steel,  8  feet  long.  It  has>  cast-iron  ends.  There  are 
two  patterns  for  ends,  at  the  discharge  of  mill ;  in  one  of 
them  the  opening  is  very  large ;  this  is  used  when  the  clay 
is  of  a  very  sticky  nature,  and  also  where  large  capacity  is 
desired.  The  other  one  has  a  smaller  opening,  and  is  used 
where  the  clay  is  of  a  short  nature,  or  where  a  smaller  capacity 
is  wanted.  The  shaft  is  made  of  hexagon  hammered  steel  3^ 
inches  diameter ;  the  knives  are  also  made  of  steel,  bolted  on 
cast  hubs  that  slip  on  the  shaft.  By  using  a  knife  of  this  kind 
much  trouble  and  expense  are  saved  should  the  knives  have  to 
be  replaced.  The  hubs,  fitting  on  the  hexagon  shaft,  allow  the 
knives  to  be  arranged  in  any  manner  desired.  Each  knife  can 
be  set  in  six  different  positions,  corresponding  with  the  six  flat 
sides  of  the  shaft,  and  by  this  arrangement  of  the  knives  the 
clay  can  be  discharged  rapidly,  or  retained  in  the  mill  longer, 
and  the  tempering  controlled  in  this  manner.  The  knives  on 
shaft  outside  of  the  discharge  head  of  mill  cut  the  clay  as  it 


134 


BRICK,  TILES    AND   TERRA-COTTA. 


MANUFACTURE  OF  TEMPERED-CLAY  BRICK.      135 

emerges  through  the  head,  and  allow  it  to  fall  to  the  machine 
or  conveyor  below.  This  device  makes  the  flow  of  clay  even 
to  the  machine,  and  cuts  the  clay  in  small  pieces,  so  that  the 
machine  will  take  hold  of  it  readily. 

The  gearing  is  very  heavy,  being  geared  six  to  one.  The 
builders  say :  "  Our  long  experience  has  taught  us  that  wher- 
ever dry  clay  is  desired  to  be  mixed  with  water  in  the  process 
of  passing  through  the  pug-mill,  that  an  open-top  pug-mill  is 
the  only  safe  machine  to  use.  The  reason  for  this  is  that  an 
open-top  pug-mill  allows  the  examination  of  the  clays  all  along 
the  course,  and  the  introduction  of  additional  water  to  even  it 
up.  Closed  pug-mills  are  only  advisable  where  the  clay  is 
tempered  before  entering  into  them,  or  where  it  runs  perfectly 
even  in  moisture  in  the  bank,  and  requires  no  additional  water. 
This  mill  will  pug  clay  for  30,000  to  60,000  brick  in  10  hours, 
depending  on  the  nature  of  the  clay  and  the  arrangement  of 
the  mixing  knives."  It  is  provided  with  a  friction  clutch  pulley 
36  inches  in  diameter,  10  inch  face.  Average  motion,  150 
revolutions  per  minute ;  weight,  4,200  pounds. 

Fig.  24  illustrates- a  Double  Geared  Pug-mill  made  by  the 
Frey-Sheckler  Co.  in  two  sizes,  viz.:  No.  5,  10  feet  long;  No. 
6,  12  feet  long. 

This  pug-mill  has  a  shell  made  of  ^  inch  boiler  steel.  The 
heads  are  made  of  cast  iron,  and  of  the  same  pattern  as  is  used 
in  their  No.  2  pug-mill. 

The  shaft  is  made  of  hexagon  hammered  steel  3  3%  inches  in 
diameter ;  the  knives  are  made  of  cast  iron  and  bolted  in  cast 
socket  hubs  that  slip  on  the  shaft,  the  same  as  in  their  No.  2 
pug-mill.  This  pug-mill  is  double  geared,  made  extra  heavy 
and  strong.  It  can  be  arranged  to  discharge  the  clay  either 
from  the  bottom  or  at  the  end. 

The  capacity  of  No.  5  pug-mill  is  for  from  50,000  to  50,000 
brick  in  10  hours;  No.  6  pug-mill  50,000  to  75,000  brick  in  10 
hours,  depending  upon  the  nature  of  the  clay  and  the  arrange- 
ment of  the  mixing  knives.  It  is  provided  with  a  friction 
clutch  pulley  36  inches  in  diameter,  10  inch  face.  Average 


136 


BRICK,  TILES   AND   TERRA-COTTA. 


MANUFACTURE   OF   TEMPERED-CLAY   BRICK.  137 

motion,    160    to    170    revolutions    per   minute;   weight,   5,700 
pounds. 

MOULDING  STIFF-CLAY  BRICK. 

For  the  moulding  of  stiff-clay  brick  many  different  machines 
have  been  made,  and  England  and  Germany  stand  prominent 
with  the  United  States  in  the  construction  of  suitable  machinery 
for  this  purpose.  We  have  selected  such  machines  of  this  class 
as  seem  to  have  the  most  prominent  features,  together  with  the 
latest  improvements  for  the  purpose  of  description. 

Before  entering  upon  a  detail  of  this  machinery  itself,  it  is 
necessary  to  give  the  reader  a  full  explanation  of  the  require- 
ments which  brick  made  by  this  class  of  machines  should  meet; 
also  reciting  the  defects  which  improper  constructions  of  the 
moulding  devices  often  impart  to  stiff-mud-made  brick.  Owing 
to  defects  in  manufacture,  brick  often  disintegrate  in  the  North- 
ern climates  by  the  action  of  the  weather. 

In  New  York,  where  the  manufacture  of  brick  reaches  over 
one  hundred  millions  per  annum,  it  was  noticed  that  stiff-mud- 
made  brick  would  not  last  as  well  as  those  made  of  soft  clays, 
and  attention  was  called  to  the  facj  in  the  National  Convention 
of  Brick  Manufacturers,  by  experienced  and  conscientious  brick 
manufacturers.  Fortunately  some  experts  of  large  experience 
in  the  manufacture  and  operating  of  brick-making  machinery 
were  present  at  the  convention,  and  as  these  experts  were  per- 
sons of  practical  knowledge  acquired  in  Germany,  England, 
Australia,  and  America,  they  afterward  pointed  out  by  publica- 
tion wherein  the  cause  of  the  disintegration  of  the  brick  could 
be  found,  namely,  in  the  improper  construction  of  the  moulding 
devices. 

A  gentleman  stated  that  he  constructed  a  machine  in  Ger- 
many, some  twenty-five  years  since,  and  obtained  a  contract 
from  a  railroad  company  to  furnish  the  brick  for  some  buildings 
along  the  road ;  the  brick  being  admired  for  their  beauty  and 
seeming  density.  After  two  winters  had  passed,  however,  these 
nice-looking  brick  commenced  to  shell  off  and  presented  a  very 
shabby  appearance.  This  led  him  to  study  the  philosophy 


138  BRICK,  TILES    AND   TERRA-CO1TA. 

pertaining  to  the  flow  of  clay  through  dies,  and  how  to  prevent 
the  lamination  of  the  clay  in  the  brick,  which  was  the  only 
cause  of  his  ill- success  in  his  first  attempt  in  making  stiff-mud 
brick.  He  found,  like  all  his  coadjutors,  that  the  flow  of  the 
clay  must  be  equalized  as  it  passes  the  mouth-piece,  and  that 
the  pressure  back  of  it  must  conform  to  these  requirements. 
The  use  of  lubricating  dies  of  proper  construction  and  change 
of  forcing  augers  remedied  the  difficulties,  and  the  brick  that 
he  afterwards  made  of  the  same  clay,  with  the  same  machine, 
are  now  as  good  as  when  they  were  put  into  the  walls ;  this 
statement  being  verified  by  an  examination  made  of  the  brick 
only  a  short  time  ago. 

Manufacturers  of  this  class  of  machinery  in  America  went 
through  the  same  experience,  but  were  later  in  discovering  the 
remedy. 

It  can  be  readily  seen,  that  when  brick  are  made  on  a  die 
that  does  not  lubricate  the  corners  properly,  the  clay  will  hang 
back  and  that  the  centre  will  flow  faster  than  the  corners.  This 
makes  a  disruption  in  the  bond  of  the  material,  and  the  brick 
will  be  moulded  with  the  clay  in  layers,  or  so  called  lamina- 
tions. 

These  laminations  are  generally  in  an  oval  form,  when  made 
in  auger  mills,  whereas  stiff-mud  brick  made  on  plunger 
machines  have  straight  laminations  across  the  narrower  cross- 
sections  of  the  brick. 

The  causes  of  these  defects  are  often  found  outside  of  the 
construction  of  the  moulding  part  of  the  machine,  being  also 
produced  when  the  clay  is  worked  too  dry,  or  when  it  has  been 
improperly  tempered. 

The  defective  brick  which  elicited  the  acknowledgments  of 
the  makers  before  the  Convention  were  made  with  a  machine  of 
excellent  construction,  but  so  designed  as  to  force  out  only  one 
stream  of  clay  for  end-cut  brick,  and  at  a  rapid  rate.  The 
opening  for  the  die  being  in  a  straight  range  with  the  end  of 
the  shaft,  hence  the  clay  was  gathered  in  from  a  large  area 
around  one  central  point,  which  caused  the  brick  to  become 
shelly  lengthwise,  when  the  clay  was  being  worked  rather  stiff. 


MANUFACTURE    OF   TEMPERED-CLAY   BRICK.  139 

To  overcome  this  objection,  the  constructors  of  the  Giant, 
Acme,  Centennial  and  Mascot  machines  have  adopted  a  die  for 
end-cut  brick,  with  two  openings,  and  use  an  auger  of  large 
dimensions.  These  orifices  are  placed  far  enough  apart  to 
avoid  this  central  point  of  the  shaft,  and  are  spaced  so  that  the 
pressure  of  the  wings  of  the  screw  propellers  acts  alike  over  the 
whole  surface  of  the  opening.  A  very  compact  and  solid  brick 
is  the  result,  even  from  non-lubricating  dies. 

When  the  die  is  made  lubricating  after  the  Niedergesaess 
Patent,  very  little  difference  is  noticed  in  the  centre  stream  of  a 
three- stream  die,  if  placed  far  enough  away  from  the  propeller. 

In  the  Acme  Brick  Machine,  the  die  front  is  made  telescopic, 
so  as  to  allow  for  such  adjustment. 

While  end-cut  brick  do  very  well  for  paving  purposes,  they 
are  not  liked  so  well  by  bricklayers,  owing  to  the  smooth- 
ness of  the  surfaces  where  the  mortar  is  put  on,  and  also  be- 
cause the  ends  are  not  so  smooth  when  cut  by  the  wire  or 
knife,  whereas  side-cut  brick  have  smooth  edges  all  around,  and 
are  just  rough  enough  to  hold  the  mortar  well. 

Until  the  Niedergesaess  Patent  Lubricating  Brick  Die  was  in- 
troduced, the  making  of  side-cut  brick  was  an  uncertain  pro- 
cess. Occasionally  a  quality  of  clay  was  found  that  would 
work  pretty  well  with  a  dry  die,  or  the  imperfect  lubricating 
dies  of  the  past,  yet  the  defects  heretofore  named  were  more 
or  less  apparent;  while  many  clays  could  not  even  be  moulded, 
owing  to  the  tendency  of  the  clay  to  stick  in  the  corners,  es- 
pecially when  the  temper  of  the  clay  was  uneven. 

There  has  heretotore  been  another  serious  trouble  in  having 
dies  retain  their  proper  size  so  that  the  brick  will  be  uniform  in 
measurement.  In  very  gritty  clay  the  wear  is  very  rapid,  even 
when  the  die  is  made  of  hard  material.  This  has  also  been 
overcome  by  the  die  which  is  illustrated  in  Fig.  25. 

NIEDERGESAESS    PATENT    LUBRICATING   BRICK    DIE. 

This  die  consists  of  a  number  of  parts,  as  shown  in  Fig.  25. 
Number  462  is  the  casing  proper,  which  contains  all  the  parts 


140 


BRICK,  TILES   AND   TERRA-COTTA. 


represented  as  spread  out  below.  This  bolts  on  to  the  mouth 
of  the  machine.  On  top  of  this  casing  two  bolts  are  shown 
sticking  out  of  the  water  reservoir,  which  is  provided  with  chan- 
nels and  holes  in  the  bottom  to  conduct  the  lubricating  fluid 


FIG.  25. 


PARTS    OF   DIE   IN    DETAIL. 


or  steam  through  the  various  channels.  The  bolts  fasten  the 
lettered  plate,  represented  in  the  foreground,  on  the  reservoir. 
The  hole  in  the  centre  of  the  plate  is  to  receive  the  connecting 
pipe  with  valve,  also  given  in  cut,  which  may  either  lead  to  the 


MANUFACTURE    OF  TEMPERED-CLAY   BRICK.  141 

boiler  or  a  water  tank,  or  if  used  for  re-pressing,  to  an  oil  re- 
servoir. 

On  the  right  are  shown  four  cast  frames  having  channels 
around  the  edges  of  them.  The  left  shows  the  sheet  steel 
liners,  which  fit  over  each  frame.  In  the  immediate  front,  four 
sheet  steel  plates  are  shown.  These  fit  into  the  first  frame  and 
make  the  sharp  corners  on  the  brick.  When  round  corners 
are  desired,  these  are  replaced  by  a  liner  similar  to  those  on 
the  left. 

The  four  round-edged  plates  in  the  foreground  are  termed 
the  aprons,  and  are  put  in  last  over  all  the  liners.  The  whole 
is  held  in  by  the  frame  represented  on  top  of  the  frame  on  the 
right.  Proper  packing,  cement  or  putty,  is  used  to  prevent 
leakage. 

The  duties  of  the  aprons  are  two-fold :  to  prevent  the  wear- 
ing of  the  liners  and  to  exclude  the  lubricant  where  not  wanted, 
so  as  to  insure  an  even  flow.  It  is  highly  necessary  that  only 
clean  fluid  be  used,  as  otherwise  the  channels  will  stop  up  and 
make  the  die  inefficient.  It  is  well  to  have  a  thin-bladed  knife 
to  put  under  the  liners  occasionally,  so  as  to  keep  them  open 
for  the  fluid  to  emerge  and  come  in  contact  with  the  clay  as  it 
passes  through.  For  some  clays  dry  steam  answers  the  pur- 
pose better  than  either  water  or  oil.  Weight,  80  pounds. 

With  this  die  a  much  larger  quantity  of  ware  is  made,  and 
with  less  power,  than  on  dies  of  any  other  construction. 

This  system  is  now  applied  by  the  Frey-Sheckler  Company 
to  other  kinds  of  dies  besides  those  for  brick,  such  as  dies  for 
moulding  flooring-tile,  grate-backs,  flue-tile,  and  hollow-blocks. 

For  building-brick  sharp  corners  are  demanded,  which  this 
die  forms  very  perfectly,  while  all  dry  dies  must  have  the  cor- 
ners more  or  less  rounded  so  as  to  assist  the  moulding  of  them. 

THE   MASCOT   MACHINE,    WITH    DAISY   CUTTING    TABLE. 

Fig.  26  illustrates  the  Mascot  Machine,  with  Daisy  Cutting 
Table,  built  by  the  Frey-Sheckler  Co,     This  machine  is  admir 
ably  adapted  to  meet  the  requirements  of  persons  having  light 


142 


BRICK,  TILES   AND   TERRA-COTTA. 


MANUFACTURE    OF   TEMPERED-CLAY   BRICK  143 

power  and  desiring  to  operate  a  factory  on  a  small  scale. 
While  embracing  the  essential  features  of  the  larger  machines, 
it  is  smaller  and  of  less  capacity. 

To  run  the  machine  to  its  full  capacity  will  require  about 
1 5  horse-power,  depending  upon  the  nature  of  the  clay.  The 
Mascot  is  adapted  to  the  manufacture  of  tile  from  2  inches  to, 
and  including,  10  inches  in  diameter;  brick  from  10,000  to 
15,000  per  day  of  10  hours,  depending  upon  the  kind  and  con- 
dition of  the  clay.  It  is  also  well  adapted  for  manufacturing 
hollow  building-blocks.  Speed,  180  revolutions  per  minute; 
friction  clutch  pulley  36  inches  by  10.  inches. 

Although  the  Daisy  Cutting  Table  is  quite  small,  and  as  only 
four  brick  are  cut  at  a  time,  it  is  well  adapted  for  cutting  from 
15,000  to  20,000  brick  in  10  hours.  One  of  its  many  good 
features  is  its  "  down  cut,"  thereby  leaving  the  brick  with 
smooth  edges.  The  abutment  plate  is  hinged.  After  the  cut 
is  made  the  table  is  moved  back,  which  releases  the  abutment 
plate,  allowing  it  to  fall  back  out  of  the  way  in  removing  the 
brick,  which  is  done  before  the  cutting-frame  is  raised.  In  its 
construction  large  wheels  are  used  to  reduce  resistance.  A 
counter-weight  is  attached  to  the  cutting-frame,  which  accel- 
erates the  cutting  of  brick.  The  Daisy  can  be  used  for  cutting 
end  and  double  wedges  if  desired.  It  is  only  intended  for  side- 
cut  brick.  The  Mascot  Machine  and  the  Daisy  Cutting  Table 
combined  occupy  a  floor  space  4  feet  by  13  feet.  Combined 
weight,  2,650  pounds. 

Fig.  27  illustrates  the  Improved  Centennial  Brick  and  Tile 
Machine,  with  New  Pattern  Side-Cut  Board  Delivery  Table,  as 
built  by  the  Frey-Sheckler  Co. 

One  of  the  many  valuable  features  of  this  machine  is  its  great 
pugging  capacity.  It  is  provided  with  two  shafts,  which  revolve 
in  opposite  directions,  one  running  at  a  speed  five  times  faster 
than  the  other. 

The  mixing  shaft  on  which  the  tempering  knives  are  attached 
is  hollow,  and  the  propeller  shaft  passes  through  it  with  a  pro- 
peller attached  on  the  outer  end ;  by  this__arrangement  com- 


144 


BRICK,  TILES   AND   TERRA-COTTA. 


MANUFACTURE   OF  TEMPERED- CLAY   BRICK.  145 

plete  pugging  is  assured,  also  the  very  best  quality  of  ware  pro- 
duced. The  mixing  shaft  is  made  of  cast  steel,  and  the  propeller 
shaft  of  forged  steel.  Its  great  forte  is  in  making  a  larger 
variety  of  work  of  superior  quality  than  any  other  machine. 

It  is  adapted  for  the  production  of  hollow  building-blocks  of 
every  description,  fire  proofing,  terra  cotta  lumber,  drain  tile, 
building  and  fire-brick. 

The  construction  throughout  is  of  the  best  and  simplest. 

The  gears  are  new  and  of  heavy  pattern,  having  5^  inch 
face,  I  ^  inch  pitch. 

It  has  a  capacity  of  15,000  to  20,000  standard  size  brick  per 
day,  depending  upon  the  kind  and  condition  of  the  clay. 

A  36-inch  diameter,  lO-inch  face  friction  clutch  pulley  is 
supplied  with  this  machine,  running  at  a  speed  of  100  revolu- 
tions per  minute. 

The  machine  proper  will  occupy  a  floor  space  of  12  feet  by 
4  ft.  6  inches. 

Approximate  weight,  4,000  pounds. 

Fig.  28  illustrates  the  Improved  Acme  Machine,  built  by 
the  Frey-Sheckler  Co. 

This  machine  is  so  well  known  among  clay-workers  that  lit- 
tle need  be  said  as  to  its  merits.  The  Acme  has  been  on  the 
market  many  years,  and  for  excellence  of  performance,  size 
considered,  it  is  to-day  without  an  equal.  It  will  be  observed 
from  the  accompanying  cut  that  the  construction  of  the  main 
frame  is  very  rigid.  The  gearing  is  remarkably  strong.  The 
auger  shaft  is  made  of  forged  steel,  provided  with  two  bearings 
ten  inches  and  twelve  inches  long  respectively.  The  auger  and 
knives  are  made  of  charcoal  chilled  iron,  rendering  them  ex- 
ceedingly durable.  All  parts  are  accessible.  The  machine  is 
so  constructed  that  the  augers  and  knives  can  be  readily  ex- 
amined and  replaced  when  necessary.  There  are  no  parts  lia- 
ble to  derangement.  Like  all  their  machines,  the  acme  is  pro- 
vided with  a  friction  clutch  pulley  36  inches  diameter,  10  inch 
face,  which  places  it  under  the  immediate  control  of  the  ope- 
rator. It  is  adapted  to  the  manufacture  of  brick,  tile  and  hollow 
10 


146 


BRICK,  TILES   AND   TERRA-COTTA. 


MANUFACTURE  OF  TEMPERED-CLAY  BRICK.      147 

blocks,  making  tile  as  large  as  20  inches  in  diameter.  On 
brick  its  capacity  is  rated  from  20,000  to  30,000  standard  size 
brick  in  ten  hours.  Speed  200  to  225  revolutions  per  minute. 
Approximate  weight  4,000  pounds.  Occupies  a  floor  space  9 
ft.  6  in.  by  5  ft. 

Any  of  the  cutting  tables  made  by  the  Frey-Sheckler  Co., 
can  be  used  in  connection  with  the  Acme  machine. 

Fig.  29  illustrates  the  Special  Bucyrus  Giant  Machine,  as 
manufactured  by  the  Frey-Sheckler  Co. 

The  mixing  shaft  is  made  of  hammered  steel,  5^  inches  in 
diameter,  hexagon,  where   the   knives   are   fitted   on,  and 
inches  in  diameter  where  the  large  spur  wheel  is  fitted  on. 

The    intermediate   shaft    is    made   of    hammered    steel, 
inches  in  diameter  where  the  intermediate  gear  and  pinion  are 
fitted  on,  and  4  inches  in  diameter  at  the  bearings. 

The  driving  shaft  is  made  of  hammered  steel  3^  inches  in 
diameter. 

The  gearing  is  of  the  latest  design,  extra  heavy  and  strong. 

The  main  spur  wheel  and  spur  pinion  are  10  inches  face, 
and  12  inches  over  housings,  2J^  inches  pitch. 

The  intermediate  gear  and  driving  pinion  are  8^  inches  face, 
and  ioj^  inches  over  housings,  2^  inches  pitch. 

Both  the  intermediate  and  driving  pinions  are  made  of  cast  steel. 

By  having  the  gearing  housed  there  is  secured  from  25  to  35 
per  cent,  more  strength  on  the  same  size  gear  than  on  the  ordi- 
nary plain  gearing.  The  manufacturers  therefore  give  a  surplus 
strength. 

The  machine  is  back-geared  12  to  I,  which  renders  a  very 
strong  and  easy  motion. 

The  driving  pulley  is  of  the  friction  clutch  pattern,  48  inches 
in  diameter,  12  inches  face.  Speed,  300  revolutions  per  minute. 

The  concaves  are  securely  fastened  to  the  front  gear  frame ; 
the  side  and  end  flanges  are  planed  and  bolted  to  each  other; 
the  flanges  are  ribbed  to  the  body.  The  opening  in  the  top 
concave  is  24  inches  by  24  inches. 

The  nozzle  is  planed  on  both  ends,  and  securely  fastened  to 
the  concaves. 


148 


BRICK,  TILES   AND   TERRA-COTTA. 


MANUFACTURE  OF  TEMPERED-CLAY  BRICK. 


149 


The  front  which  receives  the  dies  is  also  planed  on  both 
ends,  so  as  to  make  a  perfect  joint ;  it  is  secured  to  the  nozzle 
with  extra  heavy  cast-iron  hinges,  thus  enabling  the  operator 
to  clean  the  machine  or  remove  the  die  readily. 

The  front  end  of  the  machine  is  supported  with  an  extra 
long  leg,  which  is  bored  out  to  fit  the  turned  end  of  the  con- 
cave and  nozzle. 

The  gear  frames  are  made  extra  heavy,  so  as  to  give  surplus 
strength.  They  are  planed  and  fitted  together  nicely.  Both 
bearings  of  the  main  shaft  in  the  gear  frames  are  18  inches  long 
and  5  */?,  inches  in  diameter.  The  bearings  of  the  intermediate 
shaft  are  14  inches  long,  4  inches  in  diameter.  The  bearings 
of  the  driving  shaft  are  14  inches  long,  3^  inches  in  diameter. 

Capacity,  50,000  to  80,000  standard  size  brick  per  day  of  10 
hours,  depending  upon  the  quality  of  the  clay,  temper  and 
treatment.  Approximate  weight,  20,000  Ibs. 

In  addition  to  the  Special  Bucyrus  Giant  Machine,  the  Frey- 
Sheckler  Co.  also  mannfacture  the  No.  I  and  No.  2  Giant 
Machines. 


BUCYRUS    SIDE   CUT   AUTOMATIC   TABLE. 


Fig.  30  illustrates  the  Bucyrus  Side  Cut  Automatic  Table  as 
built  by  the  Frey-Sheckler  Co.  It  has  a  capacity  of  40,000  to 
100,000  brick  every  ten  hours. 


150 


BRICK,  TILES   AND   TERRA-COTTA. 
FIG.  31. 


WELLSVILLE   SIDE   CUT   TABLE. 

Fig.  3 1  illustrates  the  Wellsville  Side  Cut  Table  as  manufac- 
tured by  the  Frey-Sheckler  Co.  It  cuts  any  number  of  brick 
desired  from  20,000  to  70,000  brick  per  day. 

DRYING  THE    BRICK. 

The  different  methods  of  drying  brick  may  be  classed  as  fol- 
lows :  First,  when  brick  are  spread  out  on  the  ground  to  be 
dried  by  sunshine.  Second,  the  shed  system,  where  stiff-mud 
brick  are  hacked  under  sheds  and  dried  by  natural  air-currents  ; 
soft-mud  bricks  are  dried  on  the  same  principle  by  the  use  of 
racks  and  pallets.  Third,  by  artificial  heat — the  first  and  oldest 
method  of  employing  artificial  heat  for  desiccating  brick  being 
to  dry  them  by  laying  or  hacking  them  on  a  hot  floor.  This  is 
known  as  a  hot  floor  or  flue  dryer.  This  floor  is  heated  by  a 
system  of  flues  passing  under  it,  from  furnaces  at  one  end  to 
stack  at  the  other  end.  The  second  method  by  the  use  of  arti- 
ficial heat  is  the  tunnel  system,  where  brick  are  put  on  cars, 
either  hacked  on  the  bottom  of  car  or  resting  on  hacking  pal- 
lets. The  cars  are  passed  through  heated  tunnels,  and  when 
dry  are  carried  direct  to  the  kiln  on  the  cars.  Of  this  class 
there  are  several  kinds.  Another  plan  is  to  place  them  in  cup* 
boards,  and  drive  hot  air  through  them  by  means  of  blowers 
which  supply  heat  to  the  cupboards  through  hot-air  pipes. 

The  disadvantages  of  drying  brick  in  the  sun  are  that  they 
are  exposed  to  rain  and  frost,  and  the  percentage  of  brick  dam- 


MANUFACTURE  OF  TEMPERED-CLAY  BRICK.      151 

aged  and  lost  will  average  1 5  per  cent.  Again,  there  is  no  cer- 
tainty about  the  supply  of  sunshine  ;  while  it  is  furnished  without 
price,  it  is  also  furnished  without  regularity,  and  sometimes,  for 
two  weeks  at  a  time,  no  brick  are  dried ;  hence,  the  brick- 
maker  who  depends  on  this  process  of  drying  has  an  uncertain 
output  indeed.  Still  there  is  much  more  certainty  about  the 
output  than  there  is  about  the  number  he  may  put  into  the  kiln. 
There  are  only  six  months  in  the  year  during  which  they  can 
be  dried  in  this  way,  and  only  a  part  of  this  time  is  available. 
Where  brick  are  made  in  great  quantities,  a  large  area  for  dry- 
ing the  brick  is  needed,  as  it  must  contain  nearly  a  week's 
production.  This  necessitates  the  moving  of  the  brick  long 
distances  from  machine  to  yard  and  from  yard  to  kilns,  and  also 
the  handling  of  large  quantities  of  lumber  to  protect  the  brick, 
which  requires  a  good  deal  of  labor,  and  destroys  in  a  season 
many  thousand  feet  of  the  very  best  lumber.  The  advantages 
of  sheds  over  the  sunshine  process,  are  there  is  no  loss  by  storm, 
and  no  lumber  to  handle. 

The  pallet  system  is  advantageous  with  soft-mud  brick,  for 
they  can  be  dumped  from  the  moulds  at  the  machine.  This 
prevents  sticking  in  the  moulds,  and  when  placed  on  pallets 
they  can  be  put  in  racks  one  tier  above  another,  and  a  large 
quantity  can  be  stored  in  a  comparatively  small  space,  and 
when  the  racks  are  provided  with  projecting  roofs  or  canvas 
sides,  they  save  the  brick  from  damage  by  rain,  so  that  shed- 
drying  and  the  rack  and  pallet  system  are  great  improvements 
over  the  old  methods,  but  are  open  otherwise  to  the  same  ob- 
jections that  the  sunshine  method  is,  that  brick  cannot  be  dried 
in  damp  weather. 

The  general  advantages  of  artificial  drying  over  natural  are 
many,  without  reference  to  the  advantages  of  one  mode  of 
artificial  drying  over  another  mode  of  artificial  drying.  With 
an  artificial  dryer  and  a  machine  capable  of  producing  25,000 
brick  per  day,  a  brick-maker  can  make  six  millions  to  seven 
millions  per  year.  To  dry  without  artificial  heat  it  would  re- 
quire two  machines  of  25,000  capacity  to  produce  the  same 


152  BRICK,  TILES   AND   TERRA-COTTA. 

number  of  brick  in  a  year.  Now,  with  one-half  the  labor,  tools, 
power,  and  consequently  little  more  than  half  the  capital,  he 
produces  the  same  results.  He  then  gives  his  employes  steady 
work,  and  in  this  way  obtains  and  retains  a  better  class  of  men 
for  perhaps  less  wages.  There  is  much  less  worry  and  respon- 
sibility ;  he  has  no  anxiety  about  a  storm  coming  in  the  night 
and  damaging  or  destroying  his  day's  products,  or  perhaps  a 
week's  labor  may  be  swept  away,  and  his  yard  left  in  such  a 
condition  that  he  can  make  no  more  brick  for  several  days. 
With  proper  drying  facilities  the  manufacturer  can  contract  to 
sell  his  brick  for  future  delivery,  knowing  he  can  fill  his  orders 
without  being  compelled  to  carry  a  large  stock ;  instead  of 
having  to  make  his  brick  in  the  autumn  for  the  spring  market, 
he  can  sell  his  entire  product  up  to  the  end  of  the  year,  and 
begin  in  January  or  February  and  have  brick  ready  for  the 
early  spring  market. 

In  partially  drying  machine-made  brick  for  repressing,  soft- 
mud  brick  are  usually  carried  from  the  brick-machine  to  the 
yard  or  drying-shed,  where  they  remain  until  they  are  in  con- 
dition for  re-pressing. 

Just  here  many  have  their  greatest  difficulty,  as  the  brick  will 
dry  more  rapidly  on  the  surface  than  inside,  especially  the 
angles  and  corners,  and  by  the  time  the  centre  of  the  brick  is 
stiff  enough  to  stand  handling,  the  surface  is  too  hard  to  re- 
press. What  is  needed  at  this  point  is  to  equalize  the  moisture 
that  remains  throughout  the  brick  by  taking  the  brick  and 
setting  them  in  close  hacks ;  then  cover  them  with  canvas  or 
old  carpets  that  have  been  moistened,  let  them  remain  a  few 
hours,  when  uncovered  they  are  ready  to  re-press.  Part  of  the 
moisture  in  the  centre  has  come  to  the  surface,  and  every  part 
is  ready  for  pressure  and  handling. 

After  being  re-pressed  the  soft-mud  made  brick  are  often 
finally  dried  on  a  hot  floor  by  setting  them  on  end,  and  in  this 
way  it  is  possible  to  finally  dry  them  in  three  days.  To  set 
them  on  end  without  injury  they  must  be  pressed  quite  stiff — 
the  safer  way  is  to  place  them  on  edge  or  on  their  flat  side  to 


MANUFACTURE   OF   TEMPERED-CLAY   BRICK.  153 

dry.     Where   the   hot  floor   is  not  used,  the  brick   are   often 
placed  on  smooth  pallets  to  dry. 

Semi-plastic-clay  brick  may  be  pressed  direct  from  the 
machine,  as  they  are  then  sufficiently  dry  to  be  handled  from 
the  re-press  without  injury. 

IMPROVED    BRICK-DRYING   SHED. 

• 

The  improved  brick-drying  shed,  shown  in  Figs.  32  to  44, 
can  be  used  for  drying  either  wet  machine-made  or  hand-made 
brick. 

Fig.  32  is  an  end  elevation  partly  in  section.  Fig.  33  is  a 
plan  of  a  brick-board.  Fig.  34  is  a  plan  view  of  a  part  of  a 
bench  having  attached  thereto  a  mould-lander,  or  tilting-board, 
upon  which  is  a  brick-board.  Fig.  35  is  a  vertical  section 
taken  through  line  x  of  Fig.  34.  Fig.  36  is  a  plan  view  of  the 
hinged  boards.  Fig.  37  is  a  vertical  section  of  the  lifting 
mechanism  attached  to  the  lever  of  Fig.  36.  Fig.  38  is  a  side 
elevation  of  a  part  of  the  brick-drying  structure  partly  in  sec- 
tion. Fig.  39  is  a  plan  of  a  brick-board  mounted  on  wheels. 
Fig.  40  is  a  side  elevation  of  Fig.  39.  Fig.  41  is  a  cross-section 
of  the  ways  on  which  the  brick -board  car  moves,  and  Fig.  42 
is  a  cross-section  of  the  rafter  or  beam  &  in  Fig.  38.  Fig.  43 
is  a  plan  of  a  modification  of  the  movable  roof.  Fig.  44  is  a 
vertical  longitudinal  section  taken  through  a  line  directly  under 
the  rod  u1  in  Fig.  43. 

In  Figs.  32  and  38  a  a  are  uprights,  which  stand  preferably 
apart  at  the  same  distance  from  one  another,  being  about  equal 
to  the  length  of  the  brick-boards,  as  shown  in  Fig.  38.  The 
uprights  support  the  rafters  b  and  receive  the  cleats  c,  arranged 
onb  over  the  other,  and  in  such  a  position  as  that  when  the 
brick-boards  are  laid  from  one  series  of  cleats  to  the  opposite 
one  the  brick-boards  will  lie  approximately  level. 

The  roof  may  be  formed  so  that  it  may  be  opened  to  allow 
the  sun  and  air  to  enter,  or  be  closed  to  exclude  the  rain  or 
dew.  This  may  be  accomplished  by  pivoting  the  roof-boards 
e,  Figs.  32  and  38,  and  connecting  them  by  a  strip,/,  of  wood 


154 


BRICK,  TILES   AND   TERRA-COTTA. 


or  iron  whereby  all  the  pivoted  boards  may  be  opened  or 
closed  at  once,  directly  by  the  hand  or  by  a  lever,  as  shown  in 
Fig.  32. 

The  brick-boards  m  are  formed  with  projecting  cleats  gy  Fig. 
33,  on  the  under  side,  so  that  when  the  boards  are  placed  side 
by  side  on  the  cleats  in  the  brick-drying  structure  the  extremi- 
ties of  the  brick-board  cleats  g  will  abut,  and  thus  form  an  open- 


ing between  the  boards,  through  which  the  air  may  freely  pass. 
The  cleats  g  on  the  brick-boards  are  arranged  to  engage  with 
the  cleats  c  in  the  brick-drying  structure,  so  that  the  boards 
may  be  readily  and  securely  held  in  position  without  any 
danger  of  sliding  off.  The  manner  of  placing  the  green  brick 
upon  the  brick-board  is  as  follows :  The  tilting-board  n  being 
in  its  loading  position,  as  indicated  by  the  dotted  lines  on  Fig. 
35,  the  brick-board  is  placed  thereon,  and  is  held  in  place  by  a 


MANUFACTURE  OF  TEMPERED-CLAY  BRICK. 


155 


stop-piece  o,  and  the  workman  takes  the  mould  from  the 
machine,  and,  resting  it  upon  the  strip  r  upon  the  brick-board, 
turns  it  and  deposits  the  mould,  with  its  contents  of  green 
brick,  upon  the  brick-board  without  injury.  This  is  repeated 
until  the  brick-board  is  full,  and  when  the  last  mould  of  brick 
is  laid  on,  the  weight  of  the  brick  causes  the  tilting-board  to 
revolve,  which  then  comes  to  a  horizontal  position,  as  in  Fig. 

FIG.  38. 


-\* 


'.     FIG.  39.  9' 


FIG.  40. 


Rp.  41. 


FIG;  43. 


FIG.  44. 

35.  The  moulds  being  taken  off  of  the  bricks,  the  brick- 
board,  with  its  load  of  brick,  is  then  removed  to  the  drying 
structure,  which  is  near  at  hand,  where  they  remain  without 
further  handling  until  dry  and  ready  for  burning. 

The  tilting-board  n  is  so  constructed  or  pivoted  that  when 
the  brick-board  is  removed  it  returns  to  its  loading  position. 


156  BRICK,  TILES    AND   TERRA-COTTA. 

Several  of  these  tilting-boards  may  be  placed  between  the 
brick-machine  and  drying-racks — as  many  as  may  be  necessary. 

If  desirable,  the  brick-boards  may  be  mounted  upon  wheels, 
as  shown  in  Figs.  39  and  40,  either  grooved  or  flat,  and  move 
on  tracks  laid  upon  the  cleats,  as  in  Fig.  38.  The  cars,  after 
being  loaded  with  the  green  brick,  are  placed  upon  the  tracks 
and  moved  to  the  other  end,  one  after  the  other,  until  each 
track  is  full,  and  in  order  to  prevent  the  cars  from  striking  each 
other  too  heavily,  and  thus  displace  the  brick,  their  descent 
may  be  checked,  either  by  a  workman  or  by  other  suitable 
means.  When  the  brick-boards  are  mounted  upon  wheels,  the 
cleats  gl  on  the  under  side  of  the  brick-boards  are  placed  so 
that  they  extend  beyond  the  ends  of  the  cars,  as  shown  in  Fig. 
39,  and  thus  admit  the  circulation  of  air. 

The  rails  maybe  constructed  as  shown  in  Fig.  41.  The  rail 
j  is  secured  to  a  strip  £,  and  has  a  side-piece  /,  as  a  further 
prevention  of  the  cars  slipping  off  the  track. 

In  order  that  no  moisture  can  possibly  leak  through  upon 
the  brick,  the  inventor  provides,  in  addition  to  the  other  means, 
gutters,  as  £2,  Fig.  38,  extending  from  the  ridge-piece  to  the 
eaves,  under  the  joints  where  the  shutters  meet  the  rafters  b\ 
to  carry  off  the  water. 

The  brick-drying  structures  may  be  one  hundred  feet  long, 
more  or  less,  and  in  building  them  the  inventor  prefers  to  place 
them  so  that  the  eaves  of  one  may  touch,  or  nearly  so,  those 
of  the  other,  as  shown  in  Fig.  32,  and  at  or  under  the  point  of 
meeting  to  provide  a  gutter^3,  Figs.  32  and  38,  suitably  pitched 
and  supported,  into  which  the  gutters  b\  Fig.  38,  and  el,  Fig. 
36,  may  lead.  By  this  construction  a  covered  way  a,  Fig.  32, 
is  made  for  the  passage  of  the  workman,  and  all  the  operations 
can  be  carried  on  without  regard  to  the  weather,  and  complete 
protection  is  assured. 

DRYING  BY  THE  PALLET  SYSTEM. 

In  drying  brick  by  the  pallet  system  various  methods  are 
employed.  An  economical  and  satisfactory  system  of  drying 


MANUFACTURE   OF  TEMPERED-CLAY   BRICK.  157 

by  this  method  consists  in  delivering  the  brick  after  being 
hand-moulded  directly  from  the  mould  on  to  a  pallet  made  of 
plastering  lath  32x11  inches  in  size,  each  pallet  holding  six 
brick.  The  pallets  are  made  of  pine  lath,  by  placing  close  to- 
gether two  layers  of  lath  which  are  separated  with  five  short 
lath — one  at  each  end  and  three  dividing  the  distance  between, 
and  the  two  layers  of  lath  and  cross  lath  nailed  through  at  each 
crossing  of  the  short  lath,  which  makes  what  we  might  call  a 
lath  pad,  that  is  light  and  convenient  and  can  be  stored  in  a 
small  space. 

The  drying  cribs  are  constructed  by  setting  2//x4//  or  4//x4// 
studding  in  the  ground  in  three  rows  27  inches  apart  in  the 
cross  section  of  the  crib,  and  in  the  length  a  sufficient  distance 
to  receive  the  brick  pallets  on  cleats  nailed  to  the  cross  section 
of  the  posts.  The  two  outside  rows  of  posts  rise  seven  feet 
above  ground,  and  the  centre  row  eight  and  a  half  feet.  Upon 
the  tops  of  the  posts  a  permanent  roof  is  constructed. 

A  cross  section,  in  width  of  the  crib,  will  hold  five  pallets  of 
brick  (each  holding  six  brick).  The  cleats  on  the  post  begin 
six  inches  from  the  ground,  and  are  set  apart  so  as  to  receive 
eleven  tiers  of  pallets,  the  end  of  each  pallet  resting  on  the 
cleats,  which  gives  a  holding  capacity  of  1 10  brick  for  each  foot 
of  the  cribs'  length.  12  cribs,  130  feet  in  length,  give  a  drying 
capacity  for  over  1 70,000  brick. 

The  advantages  of  this  system  of  drying  are  the  economy  of 
ground  space,  the  avoidance  of  moisture  rising  from  the  earth, 
the  drying  in  the  shade,  the  protection  against  damage  fron? 
rains,  the  brick  are  separated  so  far  apart  as  to  dry  on  all  sides 
alike,  and  when  dry  may  remain  in  the  crib  until  removed  to 
the  kiln  or  store-shed,  and  being  handled  on  the  pallets  to  the 
kiln  they  are  not  marred  by  breakage  or  finger  marks. 

A  crib  of  the  size  indicated  would  give  a  drying  capacity  for 
about  30,000  brick  made  per  day. 

Store-sheds  in  which  to  accumulate  a  stock  of  dry  brick  to 
burn  after  the  season  for  moulding  closes  are  necessary  where 
this  system  of  drying  is  employed. 


158  BRICK,  TILES   AND   TERRA-COTTA. 

DRYING    BRICK    WITH    EXHAUST   STEAM    FROM   THE   ENGINE. 

In  whatever  system  of  steam  drying  is  employed,  it  is  essen- 
tial that  the  pipes  should  be  of  ample  size,  and  that  the  bends 
and  turns  in  the  pipes  be  as  few  as  possible,  in  order  to  obviate 
as  much  as  can  be  done  the  resistance  to  the  steam,  and  avoid 
back  pressure  upon  the  engine. 

A  right-angled  turn  has  the  same  effect  in  reducing  the 
velocity  as  increasing  its  length  about  forty  times  its  diameter 
would  have,  and  consequently  these  should  be  avoided  when 
possible. 

The  entire  economy  of  drying  with  exhaust  steam  is  neutral- 
ized if  the  back  pressure  reaches  even  as  low  as  four  pounds, 
as  the  extra  fuel  required  to  run  the  engine  will,  with  loss  of 
power  and  all  things  considered,  be  more  costly  than  to  em- 
ploy some  separate  system  of  drying. 

Of  course,  with  whatever  system  of  steam  drying  is  used,  it 
will  be  necessary  to  make  ample  provision  for  the  use  of  live 
steam  with  which  to  heat  the  drier  at  times  when  the  engine  is 
not  in  use. 

By  collecting  the  water  condensed  in  the  pipes  in  a  closed 
tank  and  pumping  it  while  hot  back  into  the  boiler,  saving  in 
fuel  should  offset  any  loss  from  reasonable  back  pressure.  From 
a  paper  by  Prof.  R.  C.  Carpenter*  we  glean  the  following  points 
of  practical  information  in  relation  to  the  construction  of  steam 
work  for  driers :  the  first  is  the  effect  of  air-traps,  the  second  is 
the  effect  of  the  condensed  water,  the  third  is  the  expansion 
due  to  the  heating  of  the  pipes. 

It  is  found  in  steam  work  that  if  we  have  a  convex  bend  in 
a  pipe,  as  in  Fig.  45,  air  will  gather  in  the  upper  portion  and 
no  amount  of  pressure  will  drive  it  out. 

Sometimes  it  is  necessary  to  have  such  bends,  and  in  that 
case  a  small  air-valve  will  be  essential,  which  can  be  opened 
and  the  air  be  allowed  to  escape. 

*  Read  before  the  Michigan  Brick,  Tile  and  Drainage  Association,  held  at  Lan- 
sing, March  2oth  and  2ist,  1888. 


MANUFACTURE   OF   TEMPERED -CLAY   BRICK. 


159 


If  the  bend  is  the  reverse  of  this,  as  shown  in  Fig.  46,  con- 
densed water  will  gather  in  the  low  portion ;  this  may  in  time 
be  blown  out  or  evaporated  by  the  steam,  but  its  action  will  be 
to  condense  the  steam  and  cause  pounding  and  hammering  in 
the  pipes.  If  such  a  construction  is  necessary,  a  drip-valve 
must  be  put  in  such  a  place  and  opened  from  time  to  time  to 
allow  the  water  to  escape. 

To  avoid  both  of  these  evils  as  much  as  possible  the  pipes 
should  ascend  to  the  highest  point  at  once,  or  in  one  continuous 
run  from  the  engine.  A  vessel  with  a  water-gauge  and  a  dis- 


charge-valve should  be  placed  so  that  this  water  can  drain  into 
it,  and  as  soon  as  it  is  full,  the  engineer  can  empty  it.  As  soon 
as  the  room  to  be  heated  is  reached  the  radiating  surface  is  in- 
creased to  the  desired  amount,  as  will  be  explained  later  on, 
and  the  pipes  are  then  made  to  descend  at  least  one  inch  in  12 
feet.  If  the  engine  is  higher  than  the  dry  kiln,  so  that  the 
pipes  can  descend  continuously,  it  will  be  much  better.  The 
best  results  in  steam  heating  are  always  obtained  when  the  con- 
densed water  flows  with  the  steam. 


160  BRICK,  TILES   AND   TERRA-COTTA. 

To  avoid  the  ill  effects  of  expansion  when  the  pipes  cannot 
be  allowed  to  expand  or  contract  freely  we  can  use  especial  ex- 
pansion joints,  but  better  still  an  arrangement  consisting  of 
three  elbows. 

The  method  of  using  the  elbows  is  shown  in  Fig.  47 ;  thus, 
if  the  ends  E  and  A  are  fixed,  the  effect  of  expansion  in  the 
pipe  E  D  will  be  to  slightly  unscrew  the  elbow  C,  and  the 
lengthening  of  the  pipe  A  B  will  also  tend  to  unscrew  the  elbow 
C,  but  at  the  other  screw  thread. 

The  radiating  surfaces  are  best  made  by  connecting  two  large 
pieces  of  pipe  called  headers  or  manifolds  together.  It  will  not 
answer  to  connect  these  manifolds  by  straight  pieces  of  pipe  as 
shown  in  Fig.  48,  for  the  reason  that  unequal  expansion  of 
these  different  lengths  would  certainly  take  place,  in  which  case 
they  would  be  broken,  but  an  elbow  must  be  inserted  in  each 
length  of  pipe  so  as  to  permit  of  independent  expansion.  The 
arrangement  would  be  somewhat  as  indicated  in  Fig.  49. 

The  pipes  that  are  used  in  steam-heating  are  then  of  two 
kinds,  or,  rather,  perform  two  offices :  One  kind  of  pipe  con- 
veys the  steam  to  the  place  where  the  steam  is  wanted ;  this  we 
will  call  a  steam  main.  The  other  pipes  expose  as  much  sur- 
face as  possible  to  the  cooling  influence  of  the  air,  and  their 
office  is  to  give  off  heat ;  we  will  term  these  heating-pipes,  and 
their  outside  surface  the  heating  surface.  We  usually  reckon 
heating  surface  in  square  feet,  as  it  is  much  more  convenient. 
Now  we  will  get  one  square  foot  of  heating  surface  with  the 
following  lengths  of  different  sized  pipes:  ^  inch  pipe,  3.6 
feet;  I  inch  pipe,  2.9  feet;  i%  inch  pipe,  2.3  feet;  i%  inch 
pipe,  1.8  feet;  2  inch  pipe,  1.6  feet. 

It  is  evident  at  once  that  any  escaping  heat  from  main  pipes 
is  a  loss,  and  should  be  prevented  as  far  as  possible  by  wrapping 
with  material  to  prevent  the  escape  of  heat.  The  size  of  the 
main  pipes,  as  we  have  seen,  will  have  to  be  larger  as  they  are 
increased  in  length. 

With  a  drying  kiln  arranged  in  this  way  and  with  the  pipes 
proportioned  as  explained  there  is  no  danger  of  failure,  and  the 
expense  can  be  quite  accurately  estimated  in  advance. 


MANUFACTURE   OF   TEMPERED-CLAY   BRICK.  l6l 

The  method  of  forcing  an  air-current  over  steam  pipes  at 
one  end  and  putting  no  pipes  under  the  dryer,  is  one  that  is 
even  more  economical  in  its  results  than  the  method  given 
above.  It  will  require  much  less  heating  surface  and  is  certain 
to  be  successful. 

STEAM  DRY  FLOORS. 

A  good  method  for  drying  brick  is  to  employ  an  iron  floor, 
flued  underneath,  the  exhaust  steam  from  the  engine  being 
turned  under  the  floor  loose. 

In  constructing  a  drying  floor  of  this  kind  the  following  are 
good  directions,  which  may  be  varied  to  suit  special  circum- 
stances :  First,  lay  down  a  bottom  floor  of  any  cheap,  suitable 
material — hard,  discolored  brick  and  bats  are  as  good  as  any- 
thing ;  lay  this  floor  with  a  slight  fall  to  an  outlet  or  drain,  so 
that  the  condensed  steam  may  be  properly  conveyed  away  in- 
stead of  being  left  to  soak  into  the  ground,  as  sometimes  is 
foolishly  done.  When  the  floor  is  laid  the  joints  should  all  be 
made  tight  with  liquid  lime  poured  over  it  and  well  ground  in. 
About  10  or  12  inches  above  this  the  iron  plates  should  be  laid. 
The  plates  should  be  as  level  as  possible,  in  order  to  make  good 
joints  and  confine  the  steam.  If  of  cast-iron  they  should  be 
not  less  than  one-half  inch  thick  and  not  more  than  two  feet 
wide ;  the  length  is  limited  only  by  the  necessity  of  being 
straight  and  the  ability  to  handle  them.  If  of  wrought-iron, 
they  need  not  be  over  one-fourth  inch  thick,  and  may  be  two 
feet  three  inches  or  (possibly)  two  feet  six  inches  wide.  The 
walls  to  carry  the  plates  should  be  chequered  or  perforated 
throughout  so  as  to  favor  the  free  circulation  of  the  steam — 
all  but  the  top  course,  which  must  be  solid.  In  laying  down 
the  plates  they  should  be  soundly  bedded  in  good  Portland 
cement.  If  the  plates  are  of  wrought-iron,  the  cross-joints 
should  be  laid  on  iron  strips,  from  wall  to  wall,  about  three  inches 
wide  and  one-fourth  inch  thick,  bedded  in  cement  same  as 
other  walls.  If  the  plates  are  of  cast-iron,  they  may  be  made 
with  a  lip  on  one  end  to  receive  the  next  plate,  thus  forming 
ii 


1 62  BRICK,  TILES   AND   TERRA-COTTA. 

the  cross-joint.  The  manner  of  taking  the  exhaust  steam  to 
the  floor  depends  a  good  deal  on  the  width ;  if  the  floor  is 
narrow,  say  not  more  than  forty  feet  wide,  the  pipe  may  be 
taken  across  one  side,  close  to  the  wall ;  the  outlet  for  the  steam 
should  be  about  two  inches,  one  under  each  row  of  plates,  that 
is,  about  two  feet  or  two  feet  three  inches  apart.  If  the  floor  is 
wider  than  forty  feet,  the  pipe  should  go  across  the  centre  of 
the  floor,  the  outlets  of  course  being  doubled — that  is,  a  row 
on  each  side  of  the  pipe — so  as  to  throw  steam  both  ways ;  as 
it  is  always  possible  that  there  may  be  some  steam  remaining 
uncondensed,  its  escape  should  be  provided  for  by  one  or  more 
outlets  into  the  open  air.  With  regard  to  the  size  of  the  pipe 
conveying  the  steam  from  the  engine  under  the  floor,  do  not 
pinch  for  room.  In  a  long  length  of  piping  there  is  a  certain 
amount  of  friction  which  should  be  compensated  for  by  in- 
creased space  in  the  pipe,  so  as  not  to  put  any  back  pressure 
on  the  engine.  Always  give  a  larger  sized  pipe  than  if  the 
engine  exhausted  in  the  air;  /.  *.,  if  the  engine  would  ordinarily 
need  a  five-inch  exhaust  pipe,  give  not  less  than  six  inches 
when  taking  the  steam  under  the  floor.  In  conclusion,  I  will 
say  that  a  very  little  reflection  is  needed  to  see  wherein  consists 
the  superiority  of  the  steam-drying  floor  over  other  steam- 
drying  systems.  In  the  one  the  heat  is  obtained  directly  and 
immediately  from  the  contact  of  the  steam  with  the  drying  sur- 
face, whereas  in  all  systems  where  the  steam  is  confined  in 
pipes  the  heat  is  obtained  second-hand  from  the  air  warmed 
by  the  radiation  from  the  steam  pipes. 

The  above  description  is  from  an  address  delivered  by  Mr. 
A.  Crossly,  of  Ironton,  Ohio,  at  the  second  annual  meeting  of 
the  National  Brick  Manufacturers'  Association. 

Exhaust  steam  from  the  engine  can  also  be  used  advantag- 
eously by  turning  the  steam  into  a  gridiron  system  of  steam 
pipes  laid  under  a  slat  floor ;  air  being  admitted  under  the 
pipes,  and  by  passing  over  them  becoming  heated,  ascending 
vertically  and  passing  out  at  the  roof  of  the  shed.  By  distribut- 
ing steam  pipes  uniformly  under  the  drying  floor  exhaust  fans 


MANUFACTURE   OF   TEMPERED-CLAY   BRICK.  163 

are  not  necessary,  as  the  heated  air  will  rise  and  escape  through 
openings  in  the  roof  without  any  artificial  aid. 

The  quantity  of  air  admitted  can  be  regarded  by  suitable 
openings  at  the  air  inlets  and  outlets,  and  the  temperature  we 
think  can  be  regulated  in  the  same  way,  and  also  by  suitable 
stop-cocks. 

Of  course  there  are  minor  detals  to  provide  for,  such  as  ex- 
pansion and  contraction  of  the  pipe — drip,  etc. 

Care  must  be  observed  also  not  to  have  the  openings  in  the 
roof  so  arranged  as  to  cause  a  current  of  air  to  form  in  the 
centre  or  near  the  roof  of  the  chamber  and  dry  the  brick  which 
happen  to  be  in  the  current,  and  not  thoroughly  dry  those  at 
the  bottom,  sides,  or  corners. 

HOW  TO  DEVISE  A  DRYER. 

Any  person  by  devoting  a  little  study  to  the  subject,  and 
possessed  of  even  small  ingenuity,  can  devise  a  dryer  adapted 
to  the  particular  clay  to  be  desiccated. 

It  is  not  necessary  to  construct  costly  brick  tunnels,  as  lumber 
is  in  many  instances  just  as  good  as  brick,  and  where  a  gentle 
heat  is  used  answers  all  purposes. 

Horizontal  dryers  are  often  made  too  long  and  with  very 
short  chimneys ;  not  giving  draught  enough  to  draw  the  hot 
air  to  where  it  is  needed.  In  such  cases  the  chimneys  must 
be  heightened,  or  an  exhaust  fan  used  to  draw  the  air  through. 

The  early  inventors  of  artificial  dryers  made  the  mistake  of 
over-heating  the  brick  or  other  wares,  and  thus  making  them 
porous  and  weak ;  besides,  their  outfit  cost  too  much  and  re- 
quired too  much  fuel.  A  mild  heat  (not  above  150°  F.)  to 
aid  in  bringing  the  moisture  to  the  surface  of  the  drying  brick, 
and  just  enough  draught  to  carry  forward  the  heat  and  take  off 
the  moisture,  is  what  is  required  of  a  good  artificial  dryer. 

A  "FLUE"  OR  "HOT-FLOOR"  DRYER 

Brickmakers  who  want  dryers  and  do  not  feel  able  to  build 
those  equipped  with  pallets,  cars,  tunnels,  tracks,  etc.,  can 


1 64  BRICK,  TILES   AND   TERRA-COTTA. 

construct  a  "  flue  "  or  "  hot-floor  "  dryer  with  less  outlay  for  ma- 
terial and  labor  than  for  any  other  form  of  reliable  dryer.  The 
following  plan  of  construction  is  most  durable  and  economical : 
The  flues  should  be  150  feet  in  length  between  the  furnaces  and 
smoke-stacks.  Grade  the  foundation  for  flues  so  that  it  rises 
12  inches  from  the  furnaces  to  the  smoke-stacks.  At  the  stack 
end  let  the  flues  open  into  a  cross  chamber,  which  connects 
them  with  the  smoke-stack ;  this  chamber  should  be  as  high  as 
the  top  of  the  flues,  and  extend  downward  12  inches  below 
bottom  of  flues,  and  about  16  inches  in  width  ;  this  allows  any 
soot  that  is  not  drawn  into  the  stack  to  fall  from  the  flue,  thus 
preventing  its  accumulation  in  the  mouth  of  the  flue.  At  the 
furnace  end  the  flues  terminate  and  rest  on  a  wall ;  here  they 
receive  heat  from  a  distributing  chamber,  which  in  turn  con- 
nects with  the  furnace;  this  chamber  should  be  16  inches  wide, 
and  about  6  inches  higher  than  the  top  of  the  flues,  and  covered 
with  an  arch  or  large  tiles ;  the  bottom  of  the  flues  should  be 
12  inches  higher  than  the  grates  in  the  furnace.  These  flues 
should  be  5  inches  wide,  separated  by  four-inch  walls,  four 
courses  high,  either  laid  dry  or  laid  in  clay  mortar,  and  covered 
with  a  brick  on  flat  or  on  edge.  These  partition  walls  can  be 
of  salmon  brick — the  covers  or  cap-brick  should  be  hard.  The 
brick  must  be  used  about  6  feet  from  the  furnaces,  and  the 
furnaces  and  chamber  should  be  lined  with  fire-brick.  These 
flues  must  be  covered  with  tempered  mud,  and  as  it  dries,  roll 
it  with  a  heavy  roller,  closing  up  openings  caused  by  shrinkage  ; 
when  too  hard  for  the  roller,  use  tamps,  and  tamp  it  until  it  is 
hard  and  nearly  dry,  then  grout  the  floor  with  thin  mud  until 
dry  and  air-tight,  then  pave  it  with  hard  brick  bedded  in  thin 
mud.  The  tempered  mud  should  be  put  on  so  that  when  the 
floor  is  finished  the  whole  thickness  including  cap-brick  and 
pavement  should  be  as  follows  :  At  the  mouth  of  the  flues  next 
furnaces  12  inches,  gradually  reduced  to  8  inches  when  half  way 
to  stacks,  then  gradually  reduced  to  5  or  6  inches  at  the  stack. 
This  floor,  if  properly  constructed,  will  dry  stiff-clay  brick 
hacked  close  on  end  once  every  48  hours,  and  will  dry  soft-mud 


MANUFACTURE   OF  TEMPERED-CLAY   BRICK.  165 

brick  on  flat  once  every  24  hours.  The  capacity  of  these  floors 
with  stiff  brick  on  end  is  10  brick  per  square  foot,  with  soft- 
mud  brick  2^  per  square  foot.  With  flues  150  feet  long  the 
smoke-stack  should  be  40  feet  high  at  least.  A  stack  of  this 
height,  with  a  flue  24  inches  square  inside,  will  answer  for  a  dry 
floor  40  feet  wide  by  1 50  feet  in  length.  A  dryer  of  this  size 
will  dry  30,000  stiff-mud  brick  or  15,000  soft-mud  brick  per 
day.  The  roof  can  be  put  on  with  single  comb,  or  a  lighter 
roof  with  double  comb,  and  a  valley  in  the  centre,  supported 
by  a  row  of  posts  through  the  centre  of  the  dryer ;  these  posts 
and  all  the  others  should  rest  on  brick  pillars,  so  that  they  are 
at  least  six  inches  above  the  top  of  the  dryer  floor ;  there  is 
then  no  danger  of  fire  being  communicated  to  them  from  the 
flues.  Most  dryers  of  this  kind  that  catch  fire,  catch  from  posts 
being  buried  in  brickwork  or  in  the  ground  near  the  flues.  The 
building  should  be  covered  with  a  shingle,  tin,  or  gravel  roof. 
You  must  have  something  that  is  water-proof.  A  dryer  roof 
that  leaks  is  little  better  than  none,  as  it  damages  brick  and 
moistens  the  floor.  The  building  should  have  eave-troughs 
and  drains  to  carry  away  surface  water,  to  prevent  the  flues 
next  the  side  of  the  building  from  becoming  damp  and  clogging 
with  soot.  When  the  flues  need  cleaning,  make  an  opening 
across  the  floor  into  the  flues,  about  every  thirty  feet,  get  a 
heavy  telegraph  wire  of  sufficient  length,  insert  one  end  into  a 
small  plug  of  >wood,  and  push  it  through  the  flues  from  one  open- 
ing to  another,  fasten  a  bunch  of  old  clothes  to  the  other  end 
of  the  wire,  and  drag  it  through  one  flue  at  a  time.  (After  this 
bundle  is  drawn  through  once,  it  is  dubbed  "  the  black  cat," 
which  is  appropriate.)  In  this  way  the  flues  can  be  thoroughly 
cleaned.  The  smoke-stack  should  be  provided  with  a  damper, 
so  that  it  can  be  closed  at  night  when  fires  are  banked  to  hold 
heat  under  the  floor.  There  should  be  a  furnace  about  3  feet 
wide  and  5  feet  long,  with  grates  3  feet  in  length,  making  9 
square  feet  of  grate  surface  for  each  8  feet  width  of  dryer,  that 
is,  a  dryer  40  feet  wide  would  require  5  furnaces  of  the  size 
mentioned.  The  slack-bin  should  extend  at  least  12  feet  from 


1 66  BRICK,  TILES    AND   TERRA-COTTA. 

the  furnaces.  Coal  slack  will  make  all  the  heat  required. 
When  coal  costs  too  much,  wood  can  be  used.  The  furnace 
may  be  the  same  size  as  for  coal,  but  for  wood  only  a  few  grates 
are  needed  in  the  middle  of  the  furnace.  Such  a  dryer  will  dry 
brick  as  well  as  the  most  costly  kinds,  but  costs  more  for  fuel 
to  run  it  and  for  labor  to  handle  the  brick,  as  the  brick  have  to 
be  rehandled,  while  in  the  tunnel-dryers  they  go  direct  from 
the  machines  to  the  dryers  on  the  drying  cars. 

DRYING  BRICK  BY  A  CURRENT  OF  HOT  AIR. 

Brick  may  be  dried  by  a  current  of  hot  air,  and  in  the  follow- 
ing manner :  The  green  brick  as  soon  as  made  are  loaded  on 
cars  and  supported  by  a  series  of  wrought-iron  pallets,  each  car 
when  fully  loaded  holding  about  500  brick.  A  series  of 
furnaces,  with  flues  extending  back  the  full  length  of  the  dryer, 
are  built  with  their  tops  flush  with  the  surface  of  the  ground. 
Over  each  furnace  a  chamber  large  enough  to  hold  six  or  eight 
cars  is  built.  These  chambers  have  a  track  laid  in  them,  and 
are  just  large  enough  to  admit  the  car  loaded  with  brick. 

The  moisture  and  products  of  combustion  are  taken  off  in  a 
chimney  at  the  rear  end.  The  green  brick  are  put  in  at  the 
farthest  distance  from  the  fire  and  moved  forward  toward  the 
fire  as  they  are  dried.  A  transfer  track  should  be  so  arranged 
as  to  permit  the  cars  to  be  taken  from  any  chamber  and  trans- 
ferred to  a  single  main  track  without  trouble.  On  account  of 
its  separate  chambers  the  construction  of  a  dryer  of  this  kind 
is  necessarily  costly,  but  these  separate  chambers  are  a  neces- 
sity with  any  system  of  hot-air  heating. 

BUCYRUS  DRYER. 

Until  a  few  years  ago,  the  greater  portion  of  all  brick  were 
dried  in  the  open  air. 

One  of  the  difficult  problems  for  solution  by  brickmakers 
has  been  the  successful  drying  of  brick  and  other  clay  products. 

The  hot-floor,  heated  by  coal  fires,  was  the  first  artificial 
dryer  known  to  the  trade. 


MANUFACTURE  OF  TEMPERED-CLAY  BRICK.      167 

About  1864,  the  iron  floor,  heated  with  exhausted  steam  by 
day  and  live  steam  by  night,  came  into  practical  use  among 
fire-brick  manufacturers.  The  next  important  step  forward  was 
the  hot-air-tunnel  dryer,  heated  with  coal  fires  and  smoke,  so 
that  when  the  brick  came  out  dry,  both  the  brick  and  the  work- 
men had  a  negroid  appearance,  caused  by  the  smoke  and  dust 
irom  the  coal  used  adhering  to  the  brick  while  in  a  moist  con- 
dition. Aside  from  this  objection,  the  danger  of  the  buildings 
being  consumed  by  fire  was  very  great.  The  extreme  waste- 
fulness, and  consequent  cost  of  drying  brick  by  this  method, 
was  the  means  of  soon  sounding  the  death-knell  of  this  dryer. 

In  or  about  the  year  1874  the  steam  tunnel  dryer  was  first 
introduced,  and  at  its  inception  was  a  very  crude  affair,  being 
built  without  any  provision  for  draft  or  circulation,  and,  owing 
to  repeated  failures,  it  was  known  by  many  brick-makers  as  a 
"sweating-box;"  but,  as  the  clay-working  industry  progressed 
year  by  year,  and  as  the  perfection  of  a  more  economical  and 
successful  dryer  became  the  great  desideratum  of  the  trade, 
strenuous  efforts  were  made  to  overcome  the  defects  of  the  first 
attempt,  resulting  in  various  modifications  of,  and  additions  to, 
the  original  design. 

Another  candidate  soliciting  the  brick  manufacturers'  favor 
was  the  tunnel  dryer,  heated  with  coils  of  steam  pipe,  and  the 
hot  air  circulated  by  a  large  revolving  fan  placed  at  one  end. 
This  process  has,  so  far,  not  met  with  any  perceptible  encour- 
agement, because  of  the  fact  that  many  clays  will  not  stand  the 
cyclone  of  hot  air  violently  thrown  upon  its  surface  by  the 
action  of  a  fan,  causing  checks  and  cracks  in  the  brick.  The 
necessity  of  constantly  keeping  a  man  employed  to  operate  a 
special  engine  day  and  night  to  run  the  fan  proved  to  be  one 
of  the  chief  elements  in  destroying  the  usefulness  and  economy 
of  this  process. 

A  subsequent  rival  was  the  steam  tunnel  dryer,  with  natural 
circulation,  effected  by  the  use  of  air-ducts  and  one  or  two 
large  stacks.  By  this  method  the  whole  amount  of  saturated 
air  is  drawn  through  and  around  the  brick  hacked  in  the  end  of 


JT       "  OF  THE.  *     ^\ 

(UNIVERSITY/ 


1 68 


BRICK,  TILES   AND   TERRA-COTTA. 


the   dry-kiln   near  the  stacks,  super-adding  moisture  thereto, 
and  tending  to  make  the  brick  very  fragile. 

To  overcome  all  the  difficulties  encountered  by  the  fore- 
going processes,  the  Frey-Sheckler  Co.  were  led  to  manufac- 
ture what  is  known  as  the  "  Bucyrus  Steam  Tunnel  Dryer." 
The  circulation  of  this  dryer  is  as  near  perfection  as  it  can 
be.  Cold  air  is  first  admitted  to  the  warm-air  chamber  in  the 

FIG.  50. 


VIEW  OF  NINETEEN -TUNNEL  DRYER.     [From  Discharge  End]. 

"attic"  of  the  dryer,  and,  after  becoming  heated,  it  is  drawn 
into  the  tunnels  by  means  of  many  warm-air  ducts,  and  is  dis- 
charged in  the  middle  of  the  track,  directly  under  the  cars  of 
brick,  through  a  double  series  of  hot  pipes,  by  which  the  air 
is  given  a  very  high  degree  of  heat.  The  air  then  passes  up- 
ward, through  and  around  the  brick  which  are  hacked  on  the 
car,  and  when  the  air  is  laden  with  moisture  it  is  carried  off  by 


MANUFACTURE    OF   TEMEERED-CLAY   BRICK.  169 

the  draft  of  vapor  stacks,  which  at  no  point  are  over  eight  feet 
away.  One  of  the  many  excellent  features  worth  attention  in 
this  dryer,  not  possessed  by  any  other,  is  that  each  tunnel  is 
built  entirely  separate  from  the  other  tunnels,  and,  while  all  of 
the  tunnels  are  under  one  roof,  they  are  separated  by  division 
walls,  and  each  tunnel  can  be  operated  independently,  or  in 
connection  with  the  others,  so  that  when  one  tunnel  of  brick  is 
dry  the  steam  can  be  shut  off  from  the  same.  Then  again, 
where  large  plants  are  erected  to  meet  the  requirements  of  large 
out-puts,  and  in  case  a  reduction  of  the  out-put  is  desired  at 
any  time,  the  dryer  can  be  cut  off  to  any  desired  capacity,  as 
each  tunnel  is  governed  by  its  own  pipes  and  valves. 

There  are  a  large  number  of  these  dryers  in  practical  use  by 
brick  manufacturers,  and  they  give  satisfactory  results.  Fig.  50 
shows  a  view  of  a  Bucyrus  Dryer,  Nineteen-tunnel,  (from  dis- 
charge end). 

SETTING    BRICK    IN   THE    KILN.* 

All  brick-makers  recognize  the  importance  of  properly  burn- 
ing their  wares.  This  cannot  be  done,  however  skilful  the 
burner  may  be  or  how  good  the  ^kiln,  unless  the  brick  have 
been  properly  set  in  the  kiln ;  and  much  of  the  bad  burning  is 
due  to  ignorant  or  careless  setting  of  the  brick.  A  slight  ob- 
struction will  change  the  course  of  heat,  it  being  most  sensitive. 
It  is  necessary  that  the  spaces  left  for  draft  be,  as  nearly  as 
practicable,  uniform  throughout  the  kiln.  Where  they  are  set 
three  over  three  or  eight  over  eight,  the  setter  has  a  guide, 
and  only  by  carelessness  can  he  go  wrong ;  but  in  the  setting  of 
the  benches  and  overhanging  courses  he  has  no  such  guide  and 
must  use  his  skill. 

Most  setters  hack  the  brick  in  the  benches,  that  is,  break 
joints.  This  is,  I  think,  a  mistake,  as  it  prevents  the  heat  from 
moving  upward  from  the  benches  to  the  body  of  the  kiln,  so 
that  all  the  heat  must  pass  through  the  overhanging  courses  to 
reach  the  body  of  the  kiln. 

*  From  an  article  by  R.  B.  Morrison,  Rome,  Georgia. 


I/O 


BRICK,  TILES   AND    TERRA-COTTA. 


The  benches  should  be  set  so  that  the  heat  can  get  into  them 
from  the  arch  or  fire-flue  and  be  able  to  pass  freely  from  the 
benches  directly  upward  into  the  kiln.  I  will  illustrate  my  idea 
by  the  following  diagram : 


FIG.  51. 


FIG.  52. 


FIG  53. 


ELEVATION. 


Fig.  51  represents  ground  plan  of  the  bench  between  eyes 
or  arches  of  kiln.  This  is  a  three-brick  bench  with  a  stretcher 
between,  known  as  a  three-and-a-third-brick  bench.  The 
brick  are  set  in  pairs  as  shown. 

Fig.  52  is  the  elevation  of  end  view  of  bench,  showing 
stretchers  in  third,  sixth  and  ninth  courses  in  middle  course  up 
to  overhangers ;  then  each  alternate  course  in  middle  between 
overhangers  in  stretchers. 

Fig.  53  is  elevation  of  bench  next  to  fire  flue  or  arch  show- 
ing first  and  second  and  fourth  and  fifth  courses  set  in  pairs, 
one  directly  over  the  other. 


MANUFACTURE  OF  TEMPERED- CLAY  BRICK.      171 

This  shows  only  six  courses.  I  think  it  better  to  set  nine 
straight  courses  as  shown  in  Fig.  52,  the  third,  sixth  and  ninth 
courses  tight  as  in  Fig.  53  ;  the  third,  sixth  and  ninth  courses 
in  middle  bench,  which  are  on  a  level  with  tight  courses  in 
bench  next  to  fire,  are  set  stretchers  as  shown  in  Fig.  52.  This 
allows  the  heat  to  pass  horizontally  into  middle  bench,  then 
vertically  between  the  pairs  and  through  stretcher  courses  into 
the  kiln.  When  they  are  set  in  pairs  they  have  one  straight  face. 
The  stretcher  between  the  courses  from  bottom  to  top  prevents 
the  fire  from  running  from  one  arch  to  the  other,  as  it  will  do 
when  one  arch  is  hotter  than  the  other,  but  still  allows  sufficient 
circulation  of  heat  through  the  bench.  There  is  but  one  tight 
course  above  the  bench,  that  is  the  binding  course,  which  is 
immediately  over  the  closing  courses — one-half  resting  on  each 
course.  This  is  set  tight  only  on  the  "quarters"  of  the  kiln, 
and  loose  next  to  the  wall  and  through  centre  of  kiln.  I  think 
in  setting  above  the  arches  they  should  be  set  with  a  little  space 
for  draft  next  to  the  wall  and  across  each  end.  Set  top  course 
same  as  the  balance,  and  use  two  courses  flat,  on  top  bottom 
course,  crosswise  of  top  edge  coiyse  and  one  inch  between 
brick,  top  course  to  be  of  good  square-burned  brick  crosswise 
of  bottom  course  and  close  together. 

In  the  manufacture  of  pressed  brick  and  of  brick  which  are 
repressed  after  they  come  from  the  dry-clay  or  mud-brick 
machines,  much  depends  upon  the  manner  and  care  shown  in 
setting  the  green  brick  in  the  kiln.  The  bottom  must  be  level, 
and  each  brick  exactly  over  the  one  it  faces,  and  not  project- 
ing either  sidewise  or  endwise,  so  as  to  have  a  perfect  face. 
They  must  then  be  water-smoked  and  burned  carefully,  and  the 
kiln  settled  level.  They  should  be  perfectly  dry  when  set,  and 
set  on  dry  common  brick  to  prevent  whitening  on  the  surface 
when  burnt. 

Some  manufacturers  do  not  use  brick  barrows  or  cars  in 
moving  the  pressed  or  re-pressed  brick  from  the  dryers  to  the 
kiln,  the  brick  when  dry  being  placed  on  pallets,  which  are 
placed  one  on  top  of  the  other. 


BRICK,  TILES   AND   TERRA-COTTA. 

The  wheelers  take  two  pallets  with  twelve  brick  and  carry 
them  to  the  kiln  on  their  shoulders ;  the  setters  take  them  from 
the  wheelers,  thus  avoiding  any  chipping  of  the  brick  in  the 
handling. 

CARS  USED   IN  HANDLING  BRICK    FOR  SETTING. 

In  all  works  producing  brick  in  large  quantities  by  ma- 
chinery, it  is  much  cheaper  in  the  end  to  place  the  brick 
directly  upon  cars  and  carry  them  to  suitably  constructed  dry- 
ers, from  whence  they  are  carried  to  the  kiln  to  be  set. 

The  cars  should  be  constructed  of  iron,  and  designed  so  that 
the  slats  can  be  turned  up  and  over  on  the  next  one,  and  the 
"  off-bearers  "  from  the  machine,  and  the  "  tossers  "  in  the  kiln 
can  stand  within  the  body  of  the  car,  close  up  to  their  work,  for 
loading  and  unloading  the  brick.  This  is  an  improvement  of 
far  more  value  than  would  at  first  appear,  for  by  standing  so 
conveniently  to  the  work,  both  to  the  off-bearing  frame  of  the 
machine  and  to  the  hacks  on  the  car,  one  hacker  or  off-bearer 
is  enabled  to  perform  much  more  work  than  he  would  do  if 
compelled  to  lean  over  the  width  of  the  car. 

The  boxes  on  these  cars  are  made  with  friction-rollers  in 
them,  and  run  without  lubrication. 

They  should  travel  so  lightly  that  a  boy  will  transport  four 
hundred  and  forty  brick  on  one  of  them  with  greater  ease  than 
a  man  will  push  a  wheelbarrow  load  on  the  best-designed 
barrow. 

At  each  end  of  each  of  the  flues  of  the  dryer  is  a  transfer  or 
switching  car,  which  transfers  the  loaded  cars  from  a  single 
track,  running  from  the  machine  on  to  any  one  of  the  six 
tracks  running  into  the  flues ;  and  in  like  manner  from  any  one 
of  the  flues  to  the  track  running  to  the  kilns. 

The  loaded  cars  are  transferred  into  any  one  of  the  kilns  of 
the  works  by  means  of  transfer  cars,  and  the  empty  ones  re- 
turned to  the  machine  by  a  return-rack,  outside  of  the  flues. 

The  whole  of  this  arrangement  may  be  under  an  inclosed 
building,  and  quite  comfortable  to  work  in  at  all  seasons. 


MANUFACTURE    OF  TEMPERED-CLAY   BRICK.  173 

Altogether,  the  first  cost  of  brick-dryers,  cars,  and  tracks  is 
more  than  for  common  drying-sheds  and  barrows,  but  the  saving 
in  the  cost  of  handling  the  brick  much  more  than  compensates 
for  this.  The  expense  for  fuel  and  attendance  while  the  brick 
are  in  the  dryers  should  not  be  charged  wholly  against  them, 
as  time  and  fuel  are  largely  saved  in  the  burning. 

The  advantage  of  running  an  establishment  in  all  weathers, 
and  twelve  months  in  the  year  instead  of  eight,  and  having 
brick  in  the  spring,  when  they  command  the  best  price,  is  too 
evident  to  need  argument,  to  say  nothing  of  the  advantage  to 
be  gained  in  giving  employment  to  your  workmen  the  whole 
year  round,  and  the  difference  in  the  cost  of  labor  between 
winter  and  summer ;  but  all  of  these  advantages  sink  into  insig- 
nificance when  the  superior  quality  of  the  brick  is  considered. 
The  brick  not  being  disturbed  from  the  time  they  are  put  on 
the  cars  until  they  are  run  into  the  kilns,  thus  avoid  two 
handlings  in  loading  on  the  barrows  for  the  two  wheelings, 
whereby  their  shape  and  angles  are  preserved,  rendering  them 
much  more  perfect  when  burnt,  and  increasing  their  value  in 
the  market. 

The  dry  car,  shown  in  Fig.  54,  is  made  by  the  Frey-Sheckler 
Co.  This  company  manufactures  its  own  cars,  and  guarantees 
the  quality  of  material  and  work. 

The  frames  are  strong  and  substantially  built,  and  provided 
with  wrought-iron  bumpers,  which  project  two  inches  from 
each  end  to  allow  ample  ventilating  space  between  the  cars. 

The  journals  are  of  the  roller-bearing  type,  as  can  be  seen  in 
the  cut,  and  are  far  superior  to  the  kind  used  by  other  manu- 
facturers, obviating  their  defects  and  absolutely  reducing  fric- 
tion to  a  minimum,  thus  producing  an  easy-running  car,  and 
prolonging  the  life  of  same  beyond  the  usual  limit.  No  oiling 
required. 

The  wheels  are  pressed  on  to  the  axles  by  hydraulic  pres- 
sure, and  are  evenly  gauged  and  nicely  balanced. 

The  cars  are  thoroughly  braced,  so  as  to  withstand  all  trans- 
verse strains,  and  will  not  go  to  pieces  when  subjected  to  hard 
and  continued  usage. 


174 


BRICK,  TILES   AND   TERRA-COTTA. 


The  Frey-Sheckler   Co.  make  a  car  designed  for   carrying 
brick  on  foot  pallets. 

Length  over  all,  7  feet  3  inches. 

Width  of  frame  over  all,  35^  inches. 

Distance  from  centre  to  centre  of  wheels,  3  feet  6  inches. 

Wheels  10^  inches  diameter,  2-inch  tread. 

Gauge,  25  inches   between  track  rails;   weight,  320  pounds. 

FIG.  54. 


They  also  make  a  car  designed  for  carrying  all  varieties  of 
stiff-mud  brick,  being  supplied  with  a  double  deck,  equipped 
with  angle  iron  upper  deck  frame,  and  as  a  binder  for  the  wood 
slats. 

Length  over  all,  7  feet  3  inches. 

Width  of  frame  over  all,  35^  inches. 

Distance  from  centre  to  centre  of  wheels,  3  feet  6  inches. 

Wheels,  \O1A  inches  diameter,  2-inch  tread. 


MANUFACTURE   OF   TEMPERED-CLAY   BRICK.  175 

Height  from  top  of  side  frame  to  under  side  of  top  deck,  17 
inches. 

Size  of  angle  iron  for  upper  deck,  I  J^  inches  x  I  %  inches 
x  T3ff  inches. 

Gauge,  25  inches  between  track  rails;  weight  425  pounds. 
Capacity  500  brick. 

Fig.  54  shows  a  strong,  serviceable  and  convenient  iron  rack 
pallet  car,  for  carrying  soft-mqd  brick  ;  it  has  two  rack  sections. 
34  inches  by  40  inches,  and  hacks  the  brick  9  tiers  high. 

Dimensions  are  6  feet  6  inches  long,  40  inches  wide,  and  4 
feet  7  inches  high  from  track  rail. 

Gauge,  25  inches  between  track  rails.  Capacity,  432  brick. 
It  is  manufactured  by  the  Frey-Sheckler  Co. 

WHEKLBARROWS. 

Wheelbarrows,  which  are  important  appliances  of  a  brick- 
yard, are  usually  of  one  of  three  different  styles  of  construction ; 
one  kind  being  for  the  purpose  of.  carrying  the  clay  from  the 
pug-mill  or  ring-pit  to  the  moulding  table,  which  variety  is 
called  a  "clay-barrow;"  another  ,,is  for  wheeling  the  green 
brick  from  the  drying-sheds  to  the  kiln,  and  this  kind  is  termed 
a  "  brick-barrow;  "  and  the  third  is  used  for  wheeling  mould- 
ing sand  to  and  from  the  drying-floors  ;  this  is  called  a  "  hopper" 
or  "  box-barrow." 

In  the  clay-barrows  the  back  is  made  slanting,- so  as  to  throw 
the  weight  of  the  clay  well  over  the  centre  of  the  wheel ;  but  in 
the  brick-barrows  the  back  is  made  so  as  to  form  right  angles 
with  the  side  bars,  and  the  wheel  protrudes  through  the  back  of 
the  wheelbarrow  about  one-quarter  its  diameter. 

The  hopper  or  box-barrow  has  all  its  sides  made  on  a  slant 
of  about  30°,  being,  of  course,  larger  at  the  top  of  the  hopper 
or  box  than  at  the  bottom.  A  great  many  of  these  barrows 
were  formerly  made  with  wooden  wheels,  and  had  iron  gud- 
geons, which  worked  in  wooden  boxes  on  the  under  side  of  the 
handles ;  but  the  majority  of  the  brickyard  barrows  are  now 
made  with  iron  wheels,  spindles  and  boxes. 


1 76 


BRICK,  TILES   AND   TERRA-COTTA. 


Sometimes  brickyard  barrows  are  so  constructed  as  to  be 
easily  folded  up  for  transportation,  or  when  not  in  use,  and  are 
employed  and  found  useful  for  brickyard  plants  which  require 
frequent  changes,  as  for  the  construction  of  tunnels,  culverts, 
etc.,  on  the  lines  of  railways  and  for  other  purposes.  Such  a 
barrow  is  shown  in  Figs.  55,  56  and  57,  and  it  consists  in  certain 
arrangements  of  parts,  whereby  a  very  strong  and  cheap  wheel- 
barrow is  produced,  which  can  easily  be  folded  for  economizing 
room  in  transportation,  and  thereafter  be  put  into  working  order 
in  a  very  little  time. 

FIG.  55. 


FIG.  56. 

When  it  is  desired  to  employ  this  form  of  wheelbarrow  for 
handling  brick,  the  back  bars  F  should  form  a  right  angle  with 
the  side  bars  A,  and  the  wheel  D  should  be  moved  forward  and 
cleave  the  back  and  bottom  about  one-fourth  of  the  diameter 
of  the  wheel,  in  order  to  relieve  the  weight  upon  the  handles, 
as  in  Fig.  58. 

Fig.  55  is  a  bottom  view  of  a  folding  wheelbarrow.  Fig.  56 
is  a  side  elevation.  Fig.  57  is  a  side  view  when  folded  up. 

When  the  wheelbarrow  is  not  in  use,  and  is  either  to  be 
stowed  away  or  packed  for  transportation,  the  nuts  are  removed 
from  the  wheel-bolt  D\  the  bolt  removed,  and  the  wheel  D 


MANUFACTURE  OF  TEMPERED- CLAY  BRICK.      I// 

taken  off.  The  braces  H  are  swung  up  until  they  meet  on  the 
inclined  edge  g*t  where  they  remain  by  means  of  friction.  The 
back-board  frame,  with  the  back-board  g,  is  now  turned  down 
upon  the  wheel-bars  C,  forming  thereby  an  extension  of  the 
bottom  B.  The  braces  M  are  now  disengaged  from  the  bolts 

FIG.  57. 


m,  and  folded  together  on  the  inclined  edge  /  of  the  cross-bar 
L.  Finally,  the  legs  K  are  swung  up  between  the  side-bars  A, 
and  the  folding  up  of  the  wheelbarrow  is  completed,  as  repre- 
sented in  Fig.  57. 

To  get  the  wheelbarrow  in  working  condition  again,  the  de- 
scribed operation  is  reversed.  The  folded  wheelbarrow  requires 
very  little  room  for  stowing  away,  and  may  be  utilized  for  many 
purposes  for  which  it  is  particularly  adapted  on  account  of  its 
large  platform. 

The  barrow  shown  in  Fig.  58  is  for  wheeling  brick,  and  it 

FIG.  58. 


has  a  large  malleable  iron  wheel,  which  is  an  aid  to  the  laborer. 
The  barrow  is  thoroughly  braced,  and  is  built  so  as  to  combine 
greatTstrength  with  lightness  of  construction,  and  with  ordinary 
care  such  a  barrow  should  run  and  do  good  service  for  ten  or 
twelve  seasons. 


12 


1/8  BRICK,  TILES   AND   TERRA-COTTA. 

The  brick-truck  shown  in  Fig.  59  is  seldom  used  for  handling 
hand-made  bricks ;  but  is  employed  for  carrying  machine-made 
bricks,  and  is  usually  built  of  two  sizes,  with  either  an  open 
platform,  as  shown  in  the  cut,  or  of  light  boards.  The  open 
top  is  used  for  carrying  brick  in  the  moulds,  while  the  close 
platform  is  used  for  carrying  them,  as  made  ready  for  hacking 
or  for  conveying  tile. 

Of  course,  the  manner  of  picking  the  brick  up  from  off  the 
cars,  barrows,  or  trucks,  whether  one  in  each  hand  or  two  in 

FIG.  59. 


each  hand,  and  tossing  them  to  the  setters,  are  details  with 
which  it  would  not  be  possible  to  deal,  as  local  custom,  nature 
of  clay,  and  kind  of  bricks  to  be  handled,  must  always  govern. 

BURNING    BRICK. 

In  Chapter  III.  we  have  already  described  the  method  of  burn- 
ing hand-made  brick,  and  as  that  method  is  analogous  to  the 
process  employed  in  the  burning  of  tempered-clay  machine- 
made  brick,  no  special  description  is  therefore  necessary. 

We  shall,  consequently,  in  the  present  instance,  confine  our- 
selves to  no  regular  description,  but  shall  collate  only  such 
informamation  as  may  be  of  practical  value  to  the  manufac- 
turers of  all  classes  of  tempered-clay  machine-made  brick. 

Fire  is  the  chemically  mixing  of  certain  combustible  sub- 
stances with  a  supporter  of  combustion  in  such  a  way  as  to 
produce  light  and  heat.  Just  what  these  elements  are,  and  the 
most  effective  manner  and  means  of  bringing  them  together  so 
as  to  produce  the  greatest  amount  of  available  heat,  are  among 


MANUFACTURE   OF  TEMPERED-CLAY   BRICK.  179 

the  most  difficult  questions  with  which  the  practical  brick  man- 
ufacturer has  to  deal. 

The  most  critical  period  in  the  process  of  brick-making  is 
the  burning  of  the  kiln.  Clay,  sand,  weather,  and  all  other 
conditions  necessary  to  the  evolution  of  the  perfect  brick  may 
be  never  so  favorable,  but  without  a  successful  burning  all  is 
failure.  The  burning  with  wood  is  both  uncertain  and  expen- 
sive. These  difficulties  consist  largely  in  the  inability  to  con- 
trol the  heat,  which  is  often  unavoidably  too  high  or  low,  and 
in  the  great  cost  of  fuel  and  the  labor  necessary  to  care  for  a 
kiln  after  it  has  been  fired.  The  arch  brick  are  frequently  much 
damaged  by  over-burning,  the  ends  exposed  to  the  fire  being 
twisted,  cracked,  or  even  melted  down,  thus  rendering  them  of 
little  value.  Then  the  percentage  of  soft  brick,  that  is,  brick 
insufficiently  burned,  is  often  a  big  item  of  loss  to  the  brick- 
maker.  These  are  found  in  the  outside  and  upper  courses. 

NUMBER    OF   POUNDS    OF    BITUMINOUS    COAL   EQUAL   TO    ONE  CORD  OF  WOOD. 

Mr.  W.  A.  Eudaly,  of  Cincinnati,  Ohio,  publishes  the  follow- 
ing statement  of  the  number  of  pounds  of  bituminous  coal  that 
are  equal  to  one  cord  of  the  various  kinds  of  wood  used  in 
brick-making.  Black  hickory  stands  at  the  head.  One  cord 
of  black  hickory  is  equal  to  1787  pounds  of  bituminous  coal. 
One  cord  of  white  oak  is  equal  to  1528  pounds,  one  cord  of 
Southern  pine  is  equal  to  1354  pounds.  It  will  thus  be  seen 
that  pine  ranks  up  pretty  well.  One  cord  of  hard  maple  equals 
1 157  pounds,  one  cord  of  beech  1150  pounds.  These  are  two 
of  the  favorite  woods  for  brick  burning.  There  are  other 
reasons  why  they  are  favorites.  They  do  not  rank  so  high  as 
fuel.  One  cord  of  hazel  equals  1148  pounds  of  coal,  one  cord 
of  Virginia  pine  1075  pounds,  one  cord  of  New  Jersey  pine 
854  pounds,  one  cord  of  cedar  764  pounds,  one  cord  of  yellow 
pine  768  pounds,  one  cord  of  white  pine  747  pounds,  one  cord 
of  spruce  674  pounds,  one  cord  of  hazel  496  pounds.  There 
is  another  thing  to  be  taken  into  consideration  in  figuring  this 
wood.  Pine  is  not  the  kind  of  pine,  beech  is  not  the  kind  of 


1 80 


BRICK,  TILES    AND   TERRA-COTTA. 


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MANUFACTURE   OF   TEMPERED-CLAY   BRICK. 


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1 82  BRICK,  TILES   AND   TERRA-COTTA. 

beach,  nor  cedar  the  kind  of  cedar  that  brick-makers  are  in  the 
habit  of  putting  into  their  kilns.  The  above  analysis  is  made 
from  thoroughly  dry  wood,  not  kiln-dried  but  well-dried  wood. 
Some  of  the  softer  woods  get  moist,  and  they  will  run  down 
much  lower  in  the  scale ;  but  the  above  estimates  are  made  on 
the  basis  of  dry  wood. 

TABLE    SHOWING   THE   VALUES    AND   PROPERTIES  OF  VARIOUS  KINDS  OF  COAL. 

On  pages  1 80  and  181  there  are  given  tables  showing  the 
value  and  other  items  of  importance  relating  to  different  varie- 
ties of  coal  from  Pennsylvania,  Maryland,  Virginia,  England, 
Scotland,  etc. 

COAL   SLACK    FOR    FUEL. 

When  coal  slack  is  used  for  fuel  in  burning  brick  it  is  cus- 
tomary to  use  coke  and  wood  for  water-smoking,  as  a  more 
regular  heat  is  obtained,  and  when  the  water-smoke  is  off  the 
firing  is  then  continued  with  coal  slack. 

When  the  coal  slack  is  of  good  quality  it  requires  about  225 
tons  to  burn  350,000  tempered-clay  brick,  and  where  the  coal 
slack  can  be  obtained  for  75  cents  per  ton,  the  cost  of  burning, 
exclusive  of  that  of  water-smoking,  is  50  cents  per  thousand. 

RECENT   PROGRESS   MADE   IN    BURNING   BRICK. 

The  progress  recently  made  in  burning  brick  has  been  almost 
as  rapid  as  the  improvements  in  the  machinery,  even  if  it  has 
not  reached  the  same  perfection.  We  are  indebted  to  Wingard, 
Morrison,  Eudaly,  and  Melcher  for  their  square-top  kilns,  and 
for  superseding  the  old  methods  of  burning  with  wood,  which 
destroyed  the  brick  in  the  arches,  and  was  expensive.  Owing 
to  the  scarcity  of  wood  in  many  localities  its  use  had  to  be 
abandoned.  It  would  be  almost  impossible  to  burn  all  our 
yearly  product  of  brick  with  wood  now,  as  it  would  require 
annually  2,500,000  cords.  This  wood,  piled  four  feet  high  and 
four  feet  wide,  would  reach  over  3,700  miles  in  length.  The 
round,  or  down-draft  kiln,  has  merits  for  face  or  hard  brick, 
but  for  large  works  the  continuous  kiln  for  burning  common 


MANUFACTURE   OF   TEMPERED-CLAY   BRICK.  183 

brick  is  the  most  saving.  Mr.  Frederick  Hoffman,  of  Berlin, 
is  the  inventor  of  this  kind  of  kiln.  They  are  in  general  use  in 
Europe,  over  100  of  them  being  in  England,  and  250  on  the 
Continent.  Mr.  Hoffman  writes  to  Mr.  B.  W.  Blair,  of  Cincin- 
nati, Ohio,  from  whose  address,  delivered  at  the  second  annual 
meeting  of  the  National  Brick  Manufacturers'  Association,  I 
have  several  times  quoted  in  this  work :  "  The  principal  advan- 
tage of  my  kiln  is  saving  of  coal.  Ordinary  brick  kilns  require 
about  one  ton  of  coal  to  4,000  brick.  Here  in  Germany 
about  three-fourths  of  all  brick  made  are  burned  in  my  kilns. 
In  England  the  Royal  Admiralty,  as  well  as  several  railroad 
companies,  have  adopted  them.  The  Russian  government 
have  adopted  them  at  the  fortresses  of  Brest-Litewsk,"  etc. 
We  believe  there  are  continuous  kilns  at  Omaha,  Neb.,  and 
Columbus,  Ohio',  but  of  their  merits  we  are  not  thoroughly 
familiar.  The  cost  of  burning  brick  in  the  Hoffman  kiln,  where 
the  cost  of  coal  does  not  exceed  $2.50  per  ton,  is  about  thirty- 
five  cents  per  thousand.  It  is  possible  to  melt  the  brick 
quicker  in  a  Hoffman  kiln  than  in  any  other,  unless  an  experi- 
enced foreman  is  in  charge.  Natural  gas,  where  it  can  be 
obtained,  exceeds  all  other  methods  of  burning.  Experiments 
are  being  made  with  oil  for  burning  brick,  and  also  with  arti- 
ficial gas  generated  at  the  kiln.  All  attention  is  turned  to 
burning  now,  and  we  may  expect  great  improvements  within  a 
few  years.  What  is  now  required  is  greater  economy  of  fuel 
in  burning  brick,  more  perfect  combustion,  and  even  in  many 
of  the  present  improved  plans  there  is  too  much  waste  of  fuel 
and  loss  of  brick  from  "spaulding"  and  melting  together. 

Even  in  the  old  open-top  kilns,  which  by  this  time  should  be 
properly  understood,  there  is  great  loss  caused  by  improper 
firing ;  only  enough  coal  should  be  thrown  in  at  each  firing  to 
make  a  light  coating  all  over  the  grate  surface,  say  four  dirt 
shovels  full ;  the  thickness  of  burning  coke  on  the  grates  should 
not  exceed  four  or  five  inches,  and  the  grates  be  kept  so  as  to 
show  a  bright  light  in  the  ash-pit  at  all  times ;  and  to  save 
grates,  hot  coals  should  never  be  allowed  to  remain  in  the  ash- 
pit. 


I  84  BRICK,  TILES   AND   TERRA-COTTA. 

There  should  be  more  space  at  the  top  for  heat  to  escape 
while  water-smoking  than  when  settling  a  kiln,  as  the  draft  is  less 
strong  at  first  for  the  reason  that  the  brick  are  cold  and  damp ; 
as  they  become  heated  and  throw  off  more  heat,  the  draft  be- 
comes stronger,  then  the  space  on  top  must  be  reduced.  This 
can  be  accomplished  in  an  open-top  kiln  by  the  platting,  the 
bottom  platting  being  laid  in  strings  one  inch  apart,  the  top 
platting  crosswise  of  bottom  platting  and  close  together. 
While  water-smoking  a  few  rows  of  the  top  platting  are  raised, 
then  as  the  heat  begins  to  escape  too  rapidly,  these  are  put  in 
their  place ;  another  way  is  to  lay  top  platting,  leaving  some 
space  between  them,  then  when  ready  to  tighten  they  are 
forced  together  and  other  brick  put  in  the  spaces.  The  former 
plan  is  preferable,  as  it  is  less  work  to  close  up  the  top,  and 
the  heat  can  be  controlled  better  while  water-smoking  with  the 
first  plan.  In  firing  any  of  the  forms  of  furnace  kilns  ordinarily 
immense  volumes  of  black  smoke  continue  to  roll  off  for  ten  or 
fifteen  minutes  after  firing,  and  when  the  kilns  are  so  burned 
as  to  prevent  the  emission  of  the  black  smoke  there  results  a 
material  saving  in  the  cost  of  burning,  and  it  involves  the  ques- 
tion of  water-smoking.  Water-smoke  is  a  product  of  heat 
coming  in  contact  with  the  combined  water  that,  is  in  the 
material,  the  brick.  If  the  brick  be  exposed  to  the  sun,  on  hot 
days,  like  we  have  in  July,  and  are  allowed  to  stay  there  two  or 
three  days,  covering  them  up  over  night  to  keep  away  the  dew, 
then  putting  them  in  the  kiln,  they  are  not  water-smoked.  Why  ? 
Because  all  the  combined  water  that  lies  between  the  little 
molecules  of  the  clay  does  not  evaporate  in  the  atmosphere. 
When  these  are  warmed  up  to  212  degrees  then  it  becomes 
steam ;  and  when  water  is  turned  into  steam  it  increases  in 
volume  1700  times,  and  one  inch  of  water  is  1700  inches  of 
steam.  This  is  one  of  the  reasons  why  when  we  begin  to  burn 
this  brick  the  brick  begins  to  swell.  Now,  this  water-smoke, 
as  we  call  it,  is  turned  into  steam  and  passes  away.  If  we  un- 
dertake to  raise  the  steam  by  putting  in  coal,  it  sends  the  car- 
bon out  of  the  top  of  the  kiln  in  smoke  and  results  in  loss. 


MANUFACTURE  OF  TEMPERED-CLAY  BRICK.      185 

In  order  to  prevent  this  loss  it  is  best  to  fire  slow  when  you 
first  begin  to  warm  your  kiln.  You  save  money  by  not  being 
in  too  big  a  hurry  when  you  commence  firing — until  you  get 
up  a  temperature  in  the  kiln.  When  you  begin  to  burn  there 
is  very  little  draft ;  after  it  begins  to  warm  and  you  get  a  heated 
atmosphere  in  the  kiln,  the  more  force  has  the  draft. 

After  a  kiln  is  "  hot"  to  the  top,  the  object  then  is  to  let  the 
heat  out  of  the  arches  as  freely  as  possible,  and  hold  it  closely 
at  the  top.  In  this  way  the  arches  are  not  too  hard,  neither 
are  there  many  pale  brick  under  the  platting.  The  heat  can 
be  driven  rapidly  out  of  the  arches  to  the  top  by  throwing  air- 
currents  of  a  moderate  degree  of  heat  into  them. 

It  is  more  economical  and  also  better  to  color  the  brick  with 
a  lively  heat  instead  of  a  dead  heat.  When  a  kiln  has  a  tardy 
draft  the  heat  remains  too  long  in  the  arches,  causing  the 
"  headers  "  to  melt  and  giving  several  courses  of  pale  red  or 
salmon  brick  on  the  top  bench,  and  also  consuming  extra  time. 
When  there  is  proper  draft  and  moving  heat,  the  heat  is  nearly 
uniform  from  bottom  to  top  and  color  of  brick  the  same,  and 
a  better,  brighter  color  than  those^  burned  with  a  dead  heat ; 
the  latter  are  really  baked  instead  of  burned. 

Practical  brickmakers  look  at  results  rather  than  theories. 

The  hydrogen  of  the  gases  from  coal  and  wood,  and  in  the 
use  of  natural  gas  and  artificial  gas  the  oxygen  necessary  to 
supply  combustion,  are  derived  from  the  atmosphere.  The  hy- 
drogen that  is  in  the  fuel  has  a  greater  affinity  for  the  oxygen 
of  the  air  than  the  carbon  has ;  and  if  the  furnace  or  arch,  or 
wherever  the  fuel  is  burned,  has  not  a  proper  supply  of  air,  a 
sufficiency  of  it,  the  hydrogen  will  take  up  the  oxygen  and  leave 
the  carbon  to  pass  in  the  kiln  unburned.  Now,  many  manu- 
facturers of  brick  find  in  their  kilns  white  brick,  and  gray  brick, 
and  striped  brick,  and  laminated  brick,  for  this  very  reason,  and 
are  not  able  to  account  for  it.  The  carbon  does  not  actually 
enter  the  body  of  the  brick  always.  In  the  majority  of  cases, 
when  the  carbon  is  unburned  in  the  furnace  or  in  the  arch,  and 
passes  into  the  kiln,  it  settles  upon  the  brick,  and  when  the 


1 86  BRICK,  TILES   AND   TERRA-COTTA. 

brick  becomes  hot  enough,  it  partially  burns,  or  burns  into  an 
ash.  If  the  kiln  or  furnace  be  not  of  proper  construction  to 
burn  the  carbon  in  the  furnace,  and  it  escapes  out  without  be- 
ing burned,  and  is  consumed  in  the  kiln,  which  can  be  shown 
is  the  case  nine  times  in  ten,  you  are  burning  your  fuel  in  your 
kiln  on  your  brick,  because  it  settles  there,  and  it  burns  there, 
and  it  is  liable  to  discolor  the  brick.  It  will  not  discolor  all 
clays,  because  there  are  certain  substances  in  the  clay  that  hold 
the  carbon  and  make  different  sorts  of  color.  It  cannot  help 
but  be  so,  and  the  idea  that  this  carbon  entered  the  body  of  the 
brick  and  caused  it  to  swell  badly  may  no  doubt  be  correct  in 
many  instances.  For  this  reason  we  know  that  generally  in 
almost  all  clays  where  the  ground  bituminous  coal  is  mixed 
with  the  green  clay,  and  the  brick  put  in  the  kiln  and  burned, 
it  swells.  The  reason  is  this  :  The  ground  coal  is  placed  in  the 
clay,  and  when  it  is  heated  sufficiently,  the  volatile  matter  is 
thrown  off;  it  must  get  out,  and  it  simply  swells  the  brick  in 
the  effort  to  escape.  It  is  a  mistaken  idea  that  the  gas  in  the 
coal  can  be  consumed  by  getting  it  hot  enough.  It  will  not 
burn  until  air  gets  to  it,  and  hence  the  gas  is  generated  before 
the  air  reaches  it,  escapes  through  the  brick,  and  for  that 
reason  the  soft  coal  cannot  be  used. 

BURNING    BRICK   WITH    NATURAL   GAS.* 

The  process  of  burning  with  gas  is  less  simple  than  that  of 
drying,  and  to  be  successfully  accomplished  requires  a  slight 
knowledge  of  the  nature  of  natural  gas,  its  action  during  com- 
bustion and  the  appearance  of  the  brick  whilst  hot.  The  pre- 
dominant element  of  natural  gas  differs  from  that  of  wood  or 
coal.  The  analysis  of  most  gases  gives  about  75  per  cent, 
hydrogen,  15  per  cent,  carbon,  and  a  small  percentage  each  of 
nitrogen  and  oxygen.  Naturally  the  products  of  combustion 

*  Partly  from  a  paper  read  by  Mr.  D.  C.  Crowley,  of  Pittsburgh,  Pa.,  at  the  second 
annual  meeting  of  the  National  Brick  Manufacturers'  Association.  Held  in  Jan., 
1888.  The  conditions  have  now  entirely  changed,  owing  to  the  exhaustion  of 
natural  gas.  C.  T.  D.,  March  4,  1895. 


MANUFACTURE  OF  TEMPERED-CLAY  BRICK.      l8/ 

differ  considerably  from  those  of  wood  or  coal ;  when  the  heated 
brick  are  observed  through  this  atmosphere,  the  shade  of  color 
seems  entirely  different  from  brick  at  the  same  temperature  in 
a  kiln  where  other  fuel  is  used.  To  this  fact  more  than  any 
other  may  be  attributed  the  failure  of  several  good  coal-burn- 
ers to  succeed  with  gas.  The  greater  affinity  or  uniting  power 
which  oxygen  possesses  for  hydrogen  over  carbon  is  another 
stone  over  which  many  have  stumbled.  If  from  any  cause  there 
is  a  greater  proportion  of  gas  to  air,  the  brick  will  be  injured, 
as  we  shall  see  in  relation  to  water-smoking  and  the  early  stage 
of  firing.  In  water-smoking  with  gas,  the  process  will  probably 
require  a  longer  period  than  with  coal,  in  order  to  preserve  the 
brick  in  their  natural  color  and  original  form.  If  haste  is  at- 
tempted, the  gas  will  not  be  thoroughly  consumed,  and  the 
oxygen  taking  up  the  hydrogen  frees  the  carbon,  which  being 
in  minute  particles  seems  to  enter  the  pores  of  the  clay.  When 
the  kiln  becomes  hotter,  these  particles  are  consumed,  and  act 
as  if  bituminous  coal-dust  had  been  mixed  with  the  clay.  The 
brick  become  spongy,  blackened  and  run  together  in  a  mass. 
Where  this  has  occurred,  I  have  s^en  ordinary  sized  brick  in 
the  bench  misshapen  and  extended  to  a  length  of  15  or  16 
inches.  Often,  when  the  draft  is  not  good,  the  carbon  will  be 
deposited  in  considerable  quantities  in  the  form  of  coke  in  the 
bottom  of  the  arch  furnace.  This  usually  occurs  from  the  im- 
proper admission  of  the  air,  which  should  enter  the  arch  in 
such  a  manner  as  to  thoroughly  mix  with  and  consume  all  the 
gas  before  coming  in  contact  with  the  brick.  In  fact,  in  the 
proper  admission  and  control  of  the  air-current  entering  the 
furnace  or  arch  is  contained  the  secret  of  successfully  burning 
natural  gas.  In  ordinary  kilns,  and  without  the  aid  of  costly 
burners  and  by  utilizing  only  the  most  simple  and  inexpensive 
contrivances,  the  brick  can  be  burned  thoroughly,  without  dis- 
coloring, and  from  wall  to  wall  and  from  bottom  to  top,  except 
the  last  course.  Certainly  to  do  this  requires  careful  watching 
and  delicate  manipulation  of  the  air-currents  from  the  moment 
the  water-smoke  starts  until  the  kiln  is  closed,  but  the  waste 


1 88  BRICK,  TILES   AND   TERRA-COTTA. 

and  soft  brick  in  such  a  kiln  are  a  very  small  percentage  when 
the  undertaking  is  completed,  which  with  ordinary  clays  is 
about  three  days.  One  day  should  be  used  in  heating  the  kiln 
throughout  a  perceptible  red,  another  in  settling  the  sides,  a 
third  the  middle,  and  the  last  in  bringing  to  terms  any  spots 
that  may  have  remained.  Seven  days  are  thus  occupied  from 
lighting  to  closing,  but  some  difficult  clays,  or  clays  that  de- 
mand a  tender  handling,  will  require  a  longer  time,  whilst 
others  can  be  done  in  a  much  shorter  period.  As  an  example 
of  the  difference  in  clays,  not  long  since  I  secured  a  sample  of 
bluish  clay  from  Haverstraw,  N.  Y.,  took  another  from  the 
light,  loamy  clay  near  Pittsburgh,  and  had  them  both  worked 
up  and  burnt  beside  the  strong  plastic  clay  of  the  Wittmer 
Brick  Co.  After  keeping  them  at  a  moderate  heat  for  some 
time  they  were  allowed  to  gradually  cool,  and  when  taken  out 
we  found  the  Haverstraw  clay  closely  fused  and  distorted  in 
shape  ;  the  loamy  clay  was  somewhat  past  color,  having  a  bluish 
tinge;  whilst  the  Wittmer  clay,  though  withstanding  a  greater 
resistance  before  fracture,  was  only  a  fair  salmon.  Where  color 
and  uniformity  of  shade  are  an  object,  a  longer  time  will  give 
better  results,  the  heating  should  be  more  gradual,  and  the 
settling  less  rapid.  When  to  cease  firing  must  be  judged  al- 
most entirely  by  the  degree  of  heat.  There  is  no  blue  smoke 
with  gas,  and  the  settle  is  not  always  a  safe  guide.  I  have  seen 
clays  with  18  inches  settle  having  seven  courses  of  soft  brick, 
whilst  in  other  burns  the  same  clay  with  18  inches  settle  gave 
good  front  brick  in  the  second  course  from  the  top.  The  best 
indication  in  the  up-draft  kiln  is  the  intensity  of  the  heat  at  the 
top.  With  a  little  experience  and  a  knowledge  of  the  clay,  the 
burner  can  judge  from  this  to  a  nicety.  In  down-draft  kilns, 
of  course,  the  heat  is  judged  by  aid  of  the  peep  holes  and  test 
brick. 

Natural  gas  is  applicable  to  all  manner  of  kilns  now  used. 
It  has  been  most  successfully  applied  to  the  up-draft  pattern, 
with  or  without  furnaces.  Those  without  furnaces  are  probably 
to  be  preferred  on  account  of  the  tendency  of  the  gas  to  rise  to 


MANUFACTURE    OF   TEMPERED-CLAY    BRICK.  189 

the  roof  of  the  furnace  and  follow  it  and  the  inner  wall  to  the 
brick  before  it  is  thoroughly  consumed.  The  Wittmer  Co.,  of 
Pittsburgh,  uses  both  patterns.  The  kilns  have  20  arches  each, 
with  4^  brick  to  the  head  and  39  brick  wide,  holding  in  the 
neighborhood  of  375,000. 

The  old  kilns  in  which  the  slack  was  used  have  3 -foot  fur- 
naces, whilst  the  new  kilns  simply  have  openings  9  by  24 
inches  in  the  2O-inch  wall.  The  results  are  about  equal,  the 
brick  being  hard  to  the  walls,  and  to  the  top,  except  one 
course,  and  free  from  whitewash  or  fire-marks,  but  in  those 
having  furnaces  the  overhangers  near  the  wall  are  slightly  dis- 
colored, while  in  those  without  furnace  only  a  half  dozen  brick 
near  the  bottom  will  be  slightly  bluish.  Gas  is  successfully 
used  in  down-draft  kilns,  especially  for  burning  tile  and  terra- 
cotta ware.  In  these  the  brick  or  ware  are  uniformly  burned, 
but  there  seems  to  be  a  slight  tendency  to  over-color.  I  do 
not  know  if  natural  gas  has  been  applied  to  continuous  kilns, 
but  feel  confident  that  it  would  succeed  in  them.  However, 
they  will  scarcely  come  into  general  use  where  this  cheap  fuel 
is  employed,  because  of  the  ease  wjth  which  it  is  applied  and 
handled  in  ordinary  kilns.  With  regard  to  the  cost  of  burning 
with  gas,  it  varies  according  to  the  situation  of  the  yard.  If 
the  owner  should  be  fortunate  enough  to  possess  a  gas  well, 
he  would  be  at  only  the  actual  cost  for  drilling  and  fitting. 
Should  the  yard  be  situated  on  a  line  that  is  anxious  for  cus- 
tom, or  where  there  are  competing  lines,  the  gas  may  be  had 
very  reasonably  under  such  circumstances.  Even  under  these 
unfavorable  circumstances  the  brick  manufacturer  is  a  gainer, 
as  he  saves  the  cost  of  labor  in  hauling,  handling,  stok- 
ing, and  moving  the  refuse  of  other  fuels,  and  has  a  superior 
quality  of  brick  with  less  waste.  One  person  can  handle  all  the 
kilns  in  a  yard  by  firing  hard  during  the  day  and  easing  up  at 
night.  The  salary  paid  to  gas-burners  is  considerably  above 
that  paid  to  others,  but  it  is  a  small  item  compared  to  the  ag- 
gregate wages  paid  to  the  army  of  men  whose  services  are  dis- 
pensed with.  A  great  amount  of  space  that  was  required  for 


BRICK,  TILES   AND   TERRA-COTTA. 

stacking  and  storing  coal  is  also  free  to  be  utilized  for  other 
purposes,  and  a  yard  can  work  the  year  round,  without  annoy- 
ing the  neighborhood  or  injuring  property. 

Mr.  J.  R.  Boice  was  one  of  the  first  to  use  natural  gas  on  its 
introduction  in  Toledo,  Ohio,  and  its  results  have  proven  satis- 
factory with  kilns  holding  even  as  many  as  1,000,000  brick 
each,  the  cost  of  burning  being  about  forty  per  cent,  less  than 
with  coal,  and  the  quality  and  color  equally  as  good  as  with 
either  wood  or  coal.  Mr.  G.  B,  Smith,  of  Haverstraw,  N.  Y., 
in  speaking  of  the  use  of  gas  made  at  the  kilns  by  his  firm  as  a 
fuel  for  burning  brick,  said  : 

"  The  cost  of  burning  brick  in  Haverstraw  with  soft  coal  at 
about  $2.50  per  ton  averages  from  85  to  95  cents  per  thousand 
for  the  fuel. 

"  The  idea  of  burning  brick  with  gas  was  new  to  us.  We 
have  had  but  very  little  trouble  in  applying  it,  and  our  burners 
have  acquainted  themselves  with  it  very  easily.  We  are  now 
burning  our  brick  at  a  cost  of  some  50  or  65  per  cent,  less  than 
with  wood,  and  the  saving  of  labor  is  still  greater  than  that. 

"  It  costs  between  30  and  40  cents  a  thousand  to  burn  brick 
with  gas.  We  burn  a  very  wide  kiln,  set  49—50  wide. 

"  We  burn  the  open-hearth  kiln,  manufacturing  the  gas  at  the 
mouth  of  our  arch.  A  pipe  runs  under  the  kiln,  supplying  the 
liquid  carbon,  and  the  steam  is  supplied  from  our  steam  boil- 
ers, and  the  gas  is  generated  at  the  mouth  of  each  kiln  and 
burnt  green.  We  actually  get  the  same  gas  they  manufacture 
for  town  service — hydrocarbon  gas.  We  get  the  gas  with 
steam.  We  can  carbonize  it  with  any  liquid  carbon.  We  are 
using  a  residuum  which  we  get  from  the  refineries  in  Ohio — a 
crude  oil,  after  the  laminated  oil  and  naphthas  are  taken  out  of 
it.  We  want  carbon  only  in  a  liquid.  Any  substance  that  con- 
tains a  larger  per  cent,  of  carbon  is  the  article  we  want.  Tar 
answers  the  same  purpose  where  it  can  be  got  cheaply. 

"  The  gas  requires  to  be  carbonized,  because  we  cannot  burn 
hydrogen  without  carbonizing  it ;  if  hydrogen  could  be  burned 
alone  in  the  kiln,  it  would  be  the  cheapest  fuel.  Of  course,  we 


MANUFACTURE   OF   TEMPERED-CLAY   BRICK.  191 

get  it  in  steam,  decomposed  by  the  heat  of  the  furnace,  super- 
heated by  steam.  Our  steam  is  made  into  hydrogen  where  it 
enters  the  mouth  of  the  kiln.  By  carbonizing  it  we  get  our 
combustion  from  a  natural  draft  supply  of  oxygen,  but  hydrogen 
alone  with  natural  draft  would  not  give  us  combustion  in  an 
open  furnace. 

"The  cost  of  wood  averages  from  $5  to  $5.50  per  cord  at 
Haverstraw,  N.  Y.,  and  the  saving  in  cost  of  fuel,  using  gas  in- 
stead of  wood,  is  from  50  to  65  per  cent.  In  many  portions  of 
the  country  the  cost  of  wood  ranges  only  from  about  $1.35  to 
$2  per  cord,  and  in  such  instances  wood  is  the  cheaper  fuel.  In 
the  cost  of  burning  by  gas,  as  stated  above,  we  estimated  the 
cost  of  wood  in  opening  the  draft,  but  not  the  cost  of  labor, 
which  is  a  separate  item.  The  size  of  the  brick  produced  by 
us  is  8  inches  long,  ^y2  wide,  2^  thick. 

"  It  is  difficult  to  say  whether  or  not  this  process  with  wood 
at  $3  a  cord  and  best  Indiana  or  Ohio  coal  at  $3  a  ton  would 
be  a  cheaper  process  of  burning  brick,  taking  all  things  into 
consideration,  labor  and  everything. 

11  There  is  the  question  of  clays  used  in  different  localities. 
The  quantity  of  wood  required  to  burn  some  clays  is  much 
greater  than  others.  It  would  depend  upon  the  cost  of  oil  and 
the  cost  of  transportation.  In  the  State  of  Ohio  oil  can  be  ob- 
tained for  about  one-half  of  what  it  costs  on  the  Hudson  river. 
With  our  clay  and  conditions  I  think  the  cost  is  less  with  oil  at 
present  prices  than  with  wood  at  prices  named.  We  have  used 
very  little  coal  there.  The  price  of  crude  oil  at  Haverstraw  is 
about  $1  a  barrel. 

"Two  burners  at  a  cost  of  $160  are  required  to  an  arch. 
The  burners  are  used  for  two-and-a-half  to  three  days  on  a 
kiln,  so  that  the  burners  would  do  work  in  a  week's  time  double 
that  of  the  old  process." 

BURNING    BRICK,  TILE,  ETC.,  WITH    CRUDE   OIL. 

In  the  burning  of  brick,  tile,  etc.,  with  natural  gas,  the  prin- 
cipal obstacle  to  be  overcome  was  the  tendency  of  the  tubes 


192  BRICK,  TILES    AND   TERRA-COTTA. 

carrying  the  fuel  to  become  choked  at  the  outer  end,  where 
they  came  in  contact  with  the  heat',  by  the  escape  of  the  more 
volatile  substance  and  the  deposit  of  the  solid  matter  in  the 
pipe.  To  obviate  this,  it  was  proposed  to  throw  the  petroleum 
into  the  arches  in  the  form  of  spray.  To  accomplish  this,  two 
methods  have  been  proposed,  compressed  air  and  super-heated 
steam.  Either  will  produce  the  effect,  and  with  proper  care  a 
good  burn  may  be  obtained ;  but  it  is  observed  that  when  air 
is  the  spraying  agent  a  portion  of  the  carbon  is  deposited  under 
the  arch,  in  the  form  of  solid  gas  carbon,  while  no  such  thing 
occurs  when  steam  is  employed.  Why  this  difference?  It  will 
be  found  in  the  different  chemical  compositions  of  the  two 
agents.  Air  is  only  about  one-fifth  oxygen,  and  when  it  has 
contributed  enough  to  burn  the  hydrogen  of  the  petroleum  and 
a  portion  of  the  carbon,  the  oxygen  is  exhausted  and  the  un- 
burnt  carbon  is  deposited — a  lost  material.  On  the  other 
hand,  steam,  being  atomized  water,  is  eight-ninths  oxygen  by 
weight,  and  as  soon  as  it  strikes  the  burning  hydrogen  of  the 
petroleum,  both  in  the  form  of  spray,  the  hydrogen  is  detached 
from  the  oxygen  to  join  that  of  the  petroleum,  and  the  oxygen 
is  liberated,  and  proves  sufficient  for  the  perfect  combustion  of 
all  the  carbon ;  hence  none  is  deposited. 

Mr.  Chas.  S.  Purington,  of  Chicago,  111.,  commenced  to  use 
petroleum  as  a  fuel  in  the  dry-houses,  and  so  successful  did  the 
experiment  prove  that  no  other  fuel  has  since  been  used  by  him 
for  drying  brick. 

The  Dye  dryer  was  the  one  employed  by  Mr.  Purington,  and 
the  fuel  used  prior  to  petroleum  was  coke,  which,  including  labor 
of  running  the  dryers,  and  handling  the  coke  and  ashes,  cost 
about  37  cents  per  thousand;  but  by  the  use  of  the  petroleum 
the  cost  of  drying  was  reduced  to  20  cents  per  thousand  brick, 
including  all  labor  that  is  incident  to  the  drying  of  brick. 

The  time  necessary  to  dry  the  brick  was  reduced  by  the  use 
of  oil  as  fuel  from  10  hours  to  8  hours,  this  saving  of  time  being 
of  itself  a  great  advantage,  as  the  output  of  the  works  could 
be  increased  20  per  cent,  without  any  increase  in  the  drying 
capacity. 


MANUFACTURE   OF  TEMPERED-CLAY    BRICK.  193 

Mr.  Purington,  speaking  of  the  use  of  petroleum  as  a  fuel  in 
a  paper  read  before  the  Indiana  Tile  and  Drainage  Association, 
said: 

"  This  expriment  with  our  dryers  proving  so  successful,  the 
question  arose,  'Why  not  burn  brick  with  oil?'  We  spoke  with 
several  fuel  oil  experts  as  to  the  feasibility  of  so  doing,  but  they 
all  thought  it  could  not  be  done  without  permanent  kilns,  which 
we  did  not  have.  Unmindful,  however,  of  their  apprehensions 
and  our  own  fears,  we  determined  to  try  it.  As  a  result  of  bad 
burns  with  wood  and  coal,  we  had  in  our  yards  quite  a  number 
of  salmon  brick ;  of  these  we  made  a  small  kiln  of  three  arches, 
adjusted  our  burners  as  seemed  best,  turned  on  our  oil,  and  at 
the  expiration  of  36  hours  we  had  converted  the  salmon  brick 
into  good,  hard,  merchantable  material.  We  then  made  a 
three-arch  kiln  of  green  brick,  and  burned  it  in  62  hours. 
These  brick  were  very  good,  but  there  were  a  few  swelled  brick 
in  the  centre  of  the  kiln.  I  thought  at  the  time  it  was  caused 
by  not  drying  off  long  enough,  but  since  then  I  have  concluded 
it  was  caused  by  putting  coal  screenings  into  the  brick,  as  we 
were  obliged  to  do  in  burning  with  wood  and  coal,  but  we  have 
not  used  any  more  screenings  since  we  commenced  using  oil. 
We  have  since  then  burned  one  six-arch  and  one  eight- arch 
kiln,  both  of  which  were  very  successful. 

"  The  cost  of  burning  was  from  35  to  50  cents  a  thousand 
cheaper  than  by  the  old  method. 

"  The  brick  were  better  than  ever  before  burnt  in  our  yard, 
and  the  waste  was  almost  nothing. 

"  The  burners  used  on  the  first  two  kilns  were  the  Smith  & 
Spaulding,  and  the  Hildreth  on  the  last  two. 

"  The  main  point  to  be  attended  in  burning  with  oil  is,  to 
burn  up  all  the  petroleum.  I  have  not  seen  any  burner  that 
made  a  perfect  combustion  of  all  the  oil  that  went  into  the  arch  ; 
that  is,  small  particles  of  oil  would  fall  upon  the  ground  in  the 
torm  of  sparks,  and  there  form  a  cake  as  hard  as  glass  when 
cold.  This,  I  believe,  is  wasted  fuel;  and  when  this  can  be 
overcome  there  will  be  a  great  saving  in  the  fuel  used.  My 
13 


194  BRICK,  TILES   AND   TERRA-COTTA. 

foreman  is  now  working  and  experimenting  on  a  burner  of  his 
own  construction,  and  I  am  almost  convinced  in  my  own  mind 
that  he  has  struck  the  key-note  of  the  problem. 

"  The  steam  used  by  us  came  from  our  engine-boilers  some 
600  feet  distant  and  required  considerable  super-heating ;  but 
where  a  boiler  is  near  the  kiln  I  think  super-heating  unneces- 
sary. For  a  ten-arch  kiln  it  would  require  about  a  ten-horse 
power  boiler.  This  could  be  moved  along  the  shed  from  kiln 
to  kiln  as  required. 

"  I  have  now  given  you  my  experience  in  the  use  of  fuel  oil. 

"  The  conclusion  I  draw  from  its  successful  use  under  the 
dryers  is  that  it  makes  a  steady  heat,  enabling  us  to  regulate  its 
degree  of  intensity  from  the  time  the  brick  or  tile  go  into  the 
houses  green  until  they  come  out  dry.  There  is  no  smoke  or 
soot  to  clog  the  flues,  and  the  steam  continually  blowing  into 
the  furnace  gives  us  at  all  times  an  excellent  draft.  Two  men, 
one  at  night  and  one  in  the  day-time,  can  attend  to  the  drying, 
while  with  other  fuel  it  takes  from  four  to  five  men  to  do  the 
same  work.  Two  men  can  easily  dry  200,000  brick  in  24  hours 
just  as  well  as  they  can  50,000. 

"  As  to  the  burning  -of  brick  I  can  only  speak  of  our  own 
clay — a  very  difficult  clay  to  burn  right.  From  the  time  we 
start  to  burn  until  the  finish  we  must  continually  force  our  fires. 
We  only  dry  off  twelve  hours.  With  wood  and  coal  it  required 
much  labor  and  constant  care,  but  with  oil  and  careful  atten- 
tion we  can  maintain  a  steady  heat  at  any  required  degree,  and 
you  can  manipulate  it  in  such  a  manner  as  to  give  any  part  of 
the  arch  the  heat  required. 

"The  kiln  never  chokes,  and  cold  spots  are  unheard-of  things. 
You  can  hold  your  fires  at  any  point.  On  one  of  three  kilns 
we  held  the  fires  on  the  head  in  the  face  of  one  of  the  severest 
storms  that  has  blown  over  Chicago  for  years — a  gale  that 
lasted  eighteen  hours — and  that  head  was  so  hot  you  could 
not  touch  it  with  your  hand. 

"The  oil  which  we  use  is  obtained  from  the  great  and  inex- 
haustible fields  of  Lima,  O. 


MANUFACTURE  OF  TEMPERED-CLAY  BRICK.      195 

"It  costs,  with  wood  and  coal,  from  80  cents  to  $1.25  per 
thousand  to  burn  my  brick ;  with  crude  oil  it  costs  40  cents 
per  thousand.  I  have  been  using  four  brick-benches,  and  I 
am  sure  I  could  use  six  brick-benches.  There  is  a  great  sav- 
ing in  the  labor  required  to  fire  the  kiln,  and  the'brick  are  well 
burned  throughout. 

"  The  steam  atomizes  the  oil,  or  it  should  do  so. 

"To  begin,  build  a  little  wood  fire  to  start  the  flame,  and 
put  one  burner  in  each  end  of  the  arches  of  27  feet  in  length, 
and  it  is  possible  to  properly  fire  an  arch  50  feet  long.  Use 
40  pounds  pressure  of  steam.  There  is  no  difference  in  the 
color  of  brick  burned  with  oil  as  compared  with  those  burned 
with  wood  or  coal. 

"  Use  oil  stored  in  a  tank  placed  higher  than  the  burners, 
and  use  a  cock  to  gauge  the  amount  of  oil  for  the  burners." 

Mr.  S.  P.  Crafts  said,  at  the  Third  Annual  Convention  of  the 
National  Association  of  Brickmakers  :  — 

"One  cord  of  beech  wood,  worth  $4,  contains  17,065,000 
heat  units;  one  ton  of  bituminous  coal,  at  $4,  contains  31,227,- 
ooo  heat  units;  four  barrels  of  fuel  ^oil,  40  gallons  each,  at  $i 
per  barrel  at  6  pounds  to  the  gallon,  gives  us  20,160,000  heat 
units. 

"  Here,  then,  we  have  data  based  on  the  cost  and  heat  values 
for  Southern  New  England,  the  variation  from  which  will  not 
be  large  for  any  of  the  brick  manufacturing  centres  in  that  re- 
gion, in  which  I  include  the  Hudson  river,  New  Jersey,  etc. 

"Now,  which  fuel  shall  we  use?  The  greatest  cost  for  labor 
in  burning  and  the  least  cost  for  fitting  up  is  with  wood,  but  it 
involves  the  largest  cost  for  fuel.  The  maximum  cost  for 
fitting  up  and  the  minimum  cost  for  labor  in  burning  is  with 
coal,  but  with  the  least  cost  for  fuel  if  all  the  heat  which  it  con- 
tains can  be  utilized.  With  oil  the  cost  of  fitting  up  is  more 
than  with  wood,  but  less  than  with  coal.  The  cost  of  burning 
with  oil  is  less  than  with  wood  but  more  than  with  coal,  unless 
a  much  greater  per  cent,  of  the  heat  of  the  oil  can  be  utilized 
than  that  of  coal.  Now  it  is  claimed  that  all  the  heat  there  is 


196  BRICK,  TILES   AND   TERRA-COTTA. 

in  the  oil  can  be  obtained,  at  least  19,000  out  of  the  20,200 
units,  and  that  with  coal  but  8,000  or  8,500  out  of  the  14,300 
units.  These  are  claimed  as  proportions  in  the  pound  weights 
of  the  two  fuels.  When  we  consider  the  cost,  they  more  nearly 
approach  each  other.  12  pounds  of  oil  cost  5  cents,  and  12 
pounds  of  coal  cost  2\  cents;  therefore  to  get  at  the  relative 
values  we  must  estimate  the  work  of  12  pounds  of  oil  and  the 
work  of  28  pounds  of  coal;  12  pounds  of  oil  at  19,000  heat 
units  gives  228,000  heat  units  as  against  224,000  at  8,000  or 
238,000  at  8,500. 

"  From  this  it  seems  that  there  is  very  little  difference  be- 
tween the  cost  of  coal  or  oil  unless  some  other  consideration 
intervenes.  But  there  is  a  consideration  of  the  lesser  expense 
of  fitting  up  for  oil,  the  saving  of  time  in  burning,  the  fewer 
hands  required,  and  the  ease  with  which  the  heat  can  be  in- 
creased. You  may  keep  your  brick  at  a  dull-red  degree  of  heat 
for  any  length  of  time  and  fail  to  burn  them  hard;  but  if  you 
can,  in  a  shorter  time,  with  oil,  get  the  requisite  temperature, 
then  you  do  the  work  in  less  time  and  at  a  saving  of  fuel,  for 
the  radiation  of  the  heat  of  a  kiln  in  six  or  seven  days  is  no 
small  item.  It  seems  to  me  that  in  this  shortening  of  time  and 
saving  thereby  is  the  principal  argument  in  favor  of  oil  over 
coal ;  but  it  becomes  us  to  consider  whether  the  difference  of 
the  percentage  of  heat  utilized  under  a  boiler  when  burning  oil 
or  coal  will  hold  good  when  diffused  in  and  through  a  kiln  of 
brick.  I  do  not  think  it  will,  for  a  kiln  seems  to  take  up  all  the 
heat  of  combustion  in  either  case,  certainly  until  the  last  stage 
of  burning,  when  the  blanket  of  steam  ceases  to  hold  down  the 
heat  as  in  the  earlier  stages,  a  condition  very  different  from 
the  smoke-stack  of  a  boiler. 

"Wood  is  the  simplest  and  most  expensive  fuel  in  most 
localities,  certainly  in  localities  where  the  greatest  number  of 
brick  are  made,  but  between  coal  and  fuel  oil  it  is  an  open 
question  yet  to  be  determined  which  is  the  better,  by  a  longer 
and  more  thorough  test. 

"I  have  used  coal  at  a  cost  of  about  50  cents  per  1,000,  and 


MANUFACTURE  OF  TEMPERED-CLAY  BRICK.      197 

am  now  trying  oil  in  the  latter  stage  in  burning  to  get  a  larger 
volume  of  heat  and  to  deepen  the  color  of  the  brick  when 
burned.  We  have  just  finished  burning  a  kiln  of  19  arches, 
containing  45  1,000  brick,  using  67  tons  of  coal  at  $4.25  per  ton, 
making  the  cost  per  thousand  63  &  cents.  This  kiln  of  45 1,000 
brick  contains  15  tons  of  coal-dust  as  against  18  tons  in  the 
same  number  of  brick  made  last  year.  This  amount  and  the 
height  (six  brick  higher  than  last  year)  may  account  for  the 
longer  time  and  greater  relative  consumption  of  coal  than 
usual;  two  hands  do  the  work.  We  set  52  brick  high  to  econ- 
omize the  shed  room,  but  are  satisfied  that  46  high  is  better 
and  more  economical. 

Mr.  D.  V.  Purington,  of  Chicago,  111.,  said  at  the  third  annual 
convention  of  the  National  Association  of  Brickmakers :  "  I 
have  burnt  this  year,  1888,  a  little  over  28,000,000  brick  with- 
out using  a  stick  of  wood  or  a  pound  of  coal — entirely  with  oil. 
Of  course,  my  brick  are  artificially  dried.  We  have  taken  out 
of  each  brick,  from  the  time  it  was  made  till  it  was  set  in  the 
kiln,  a  pound  and  a  quarter  of  water,  so  they  are  when  set 
about  as  dry  as  can  be  got,  practically.  We  start  one  side  of 
the  kiln  three  or  four  hours  before  we  do  the  other,  and  we  get 
the  heat  up  just  as  fast  as  we  can  get  the  draft  started.  When 
we  first  start,  of  course,  wifhout  the  arches  being  heated  at  the 
sides  to  form  a  combustion,  we  have  to  burn  more  oil.  Our 
fuel  is  oil,  and  we  burn  on  an  average  four  days,  where  the 
average  was  about  seven  days  and  a  half  before.  The  kilns 
used  are  24  arches  each,  and  where  we  used  five  men  before 
we  now  use  two.  There  are  no  ashes  to  haul  away,  no  coal  to 
unload.  Our  fuel  is  unloaded  with  a  little  steam  pump,  and  it 
is  then  ready  to  be  drawn  by  gravitation  from  the  tank  to  the 
kiln.  I  can  state  unequivocally  that  I  know  of  no  inducement 
other  than  a  pecuniary  one,  that  would  lead  me  to  go  back  to 
burning  common  brick,  artificially  dried,  with  wood  or  coal. 
I'm  not  up  on  heat  units,  and  shall  endeavor  to  talk  in  a  lan- 
guage that  brickmakers  can  all  understand.  I  don't  know  a 
unit  of  heat ;  wouldn't  know  a  dozen  if  I  should  see  them  right 


198  BRICK,  TILES   AND   TERRA-COTTA. 

here.  The  cost  of  fuel  has  been,  for  oil,  an  average  of 
cents  per  1,000.  Before  we  understood  oil  and  its  uses,  we 
used  a  great  deal  more  than  we  do  now,  and  we  are  all  the 
time  improving  upon  it.  Any  science  so  new  as  the  burning 
of  brick  with  crude  oil  is  susceptible  of  great  changes,  and  I 
expect  it  to  improve  for  the  next  ten  years.  The  exact  total 
cost  of  burning  brick  so  far  with  me,  I  have  been  unable  to  as- 
certain, for  this  reason — I  take  my  steam  from  a  stack  of  three 
boilers,  and  the  same  steam  from  the  three  boilers  is  used  for 
running  my  machines  in  the  day-time  and  also  for  my  kilns, 
and  for  burning  brick ;  so  I  have  been  unable  to  divide  the 
amount  of  steam  used  for  burning  brick,  and  the  only  way  I 
can  get  at  it  is  relatively,  and  my  figures  show  the  total  cost 
for  labor,  fuel,  oil,  and  coal  for  burning  brick  this  year  has  been 
53  y^  cents,  as  compared  last  year  with  92  cents,  when  using 
wood  and  coal. 

"  If  the  cost  of  fuel  was  the  same,  if  it  cost  me  just  as  much 
for  oil  and  wood  to  make  steam  as  it  did  for  wood  and  coal,  I 
would  still  burn  with  oil.  My  arch  brick,  aside  from  the  first 
1 8  inches,  are  the  best  I  have  in  the  kiln.  There  isn't  a  check 
end  brick  or  discolored  brick,  or  anything  that  would  damage 
them ;  they  are  really  the  best  in  the  kiln. 

"To  use  a  burner  with  an  aperture  sufficiently  small  to  make 
a  light  fire  results  in  clogging  that  aperture  with  carbon.  The 
hydro-carbon  burner  made  in  New  York,  and  which  Mr.  Smith 
represented  last  year,  is  in  many  respects,  I  think,  the  most 
complete  oil-burner  I  have  ever  seen.  There  were  five  aper- 
tures about  the  size  of  a  knitting-needle  in  that  burner. 

"The  first  three  kilns  we  burnt  we  had  a  good  deal  of  diffi- 
culty in  handling  our  fires  with  oil  and  getting  the  centres  and 
outside  corners  and  ends  hot,  and  in  throwing  the  heat  to  any 
part  of  the  kiln  desired ;  but  now  to  get  the  heat  we  let  one 
side  go  very  light  and  fire  the  other  heavily,  so  that  the  two 
flames,  instead  of  meeting  in  the  centre,  face,  just  as  in  the  old- 
fashioned  way.  I  can  get  any  heat  I  want  inside  of  two  min- 
utes. We  use  slack  coal  on  the  outside  courses.  After  start- 


MANUFACTURE  OF  TEMPERED-CLAY  BRICK.      199 

ing  the  fire,  and  the  brick  begin  to  sweat,  which  all  brick  will 
do,  there  is  no  difficulty  in  getting  the  fire  up  through  them ; 
and  there  is  one  advantage  in  the  use  of  oil  over  the  use  of 
coal :  in  forcing  your  fire  it  is  an  absolute  impossibility  to  choke 
your  kiln  with  oil,  and  you  have  no  ashes,  no  dust." 


CHAPTER  V. 

CHAMBERS    BRICK   MACHINE. 

AMONG  the  many  efforts  made  to  perform  by  machinery  the 
various  manipulations  of  brick-making,  the  inventions  of  Cyrus 
Chambers,  Jr.,  of  Philadelphia,  Pa.,  stand  conspicuous  as  suc- 
cessful machines  for  the  purpose  designed.  Recognizing  that 
a  thoroughly  tempered  brick  possesses  certain  essential  qualifi- 
cations not  found  when  the  tempering  process  was  omitted, 
and  that  to  produce  the  finer  grades  of  face  or  front  brick, 
known  as  "  Pressed  Brick,"  requires  especial  care  in  handling 
and  forwarding,  the  Chambers  Brothers  Company,  of  Philadel- 
phia, Pa.,  has  devoted  particular  attention  to  the  development 
and  manufacture  of  machinery  that  stands  pre-eminent  for  the 
production  of  superior  quality  of  common  building  brick  with 
the  greatest  economy. 

Mechanical  skill  of  a  high  order  is  evidenced  in  the  general 
design  of  the  Chambers  machine,  and  a  thorough  familiarity 
with  the  materials  to  be  worked  and  their  action  on  machinery 
is  shown  in  the  ready  means  provided  for  the  cheap  renewal  of 
such  parts  as  must  of  necessity  in  time  wear. 

When  the  clay  to  be  worked  is  unusually  strong,  has  lime- 
stone in  it,  or  has  hard,  tough  lumps  that  will  not  temper  in  an 
ordinary  pug-mill  or  ring-pit,  it  is  passed  through  rollers,  or 
grinding  mills,  before  being  fed  into  the  hopper  of  the  brick 
machine. 

The  Chambers  Single  Conical  Rolls,  with  detachable  shells, 
illustrated  in  Fig.  60,  serve  to  expel  the  larger  stones,  break  up 
the  lumps  of  clay,  and  help  to  mix  the  clay  and  sand  together. 

These  rolls  are  cast  in  "  Shells  "  or  "  Telescopes,"  so  that  the 
wearing  parts  can  be  renewed  without  replacing  any  of  the 
other  portions. 

(200) 


CHAMBERS   BRICK    MACHINE. 


201 


2O2 


BRICK,  TILES   AND   TERRA-COTTA. 


From  beneath  these  rolls  the  clay  is  carried  immediately  to 
the  hopper  of  the  brick-machine.  The  Chambers  machines 
mix  and  temper  the  clay  with  water  as  they  use  it,  without  ad- 
ditional handling.  After  tempering  the  clay  they  form  it  into 
parallel  bars  the  desired  width  and  thickness  for  a  brick,  sand 
the  surface,  cut  the  bar  thus  formed  into  uniform  lengths,  and 
then  deliver  the  brick  so  moulded  and  sanded,  at  any  con- 
venient distance  from  the  machines,  sufficiently  stiff  to  be  im- 
mediately wheeled  and  hacked  in  the  shed  or  on  drying  cars. 

THE   TEMPERING    DEVICE. 

The  tempering  portion  of  the  machine  (Fig.  61)  consists  of 
a  strong  cast-iron  conical  case,  in  which  revolves  a  horizontal 

FIG.  61. 


shaft  into  which  are  set  spirally,  strong  tempering  knives,  or 
blades  of  wrought  iron  or  steel  (see  Fig.  62),  so  that,  as  they 
pass  through  the  clay,  they  move  it  forward.  The  clay  being 
stiff,  and  not  having  much  water  on  it,  is  not  liable  to  slip  be- 
fore the  knives,  but  is  cut  through  and  through,  and  thoroughly 
tempered,  the  air  escaping  back  through  the  untempered  clay, 
so  that  by  the  time  the  clay  reaches  the  small  end  of  the  tem- 
pering case  it  is  ready  to  be  formed  into  brick. 

On  the  end  of  the  tempering  shaft  is  secured  a  conical  screw 
of  hard  iron,  which  revolves  in  a  hard  iron  conical  case,  the 
inside  of  which  is  ribbed  or  fluted  lengthwise,  so  as  to  prevent 


CHAMBERS   BRICK   MACHINE. 


203 


the  clay  revolving  in  it,  and  is  hard,  to  prevent  wearing  (see 
Fig.  61). 

The  screw  being  smooth  and  very  hard,  the  clay  slides  on  the 
screw,  thus  becoming,  as  it  were,  a  nut;  the  screw  revolving 
and  not  being  allowed  to  move  backward,  the  clay  must  go 
forward,  sliding  within  the  screw-case.  This  case  is  heated  by 
steam,  which  facilitates  the  sliding  of  the  clay  and  saves  con- 
siderable power. 

This  operation  further  tempers  the  clay,  and  delivers  it  in  a 
solid  round  column  to  the  forming-die. 

Plastic  materials,  moving  under  pressure,  follow  the  laws  of 
fluids. 

The  great  difficulty  heretofore  experienced  in  machines  ex- 

FIG.  62. 


pressing  plastic  materials  has  been  to  make  the  flowing  mass 
move  with  uniform  velocity  through  all  its  parts.  As  the 
channel  of  a  river  flows  faster  than  the  shallow  portions,  or 
those  near  the  banks,  so  does  clay  move  through  a  die,  the 
friction  of  the  corners  holding  them  back,  while  the  centre 
moves  more  freely.  This  difficulty  is  overcome  by  the  pecu- 
liar form  of  the  "  former,"  which  is  so  shaped  as  to  facilitate 
the  flow  of  the  clay  to  the  corners,  and  by  this  means  the  angles 
of  the  bar  of  clay  are  re-enforced  and  made  very  solid  and 
sharp,  thus  insuring  perfectly  square  and  well-defined  corners 
to  the  brick. 


20.|  BRICK,  TILES   AND   TERRA-COTTA. 

The  "former"  is  secured  to  the  screw-case  by  a  hinge  and 
swinging  bolt,  so  that  it  may  be  quickly  swung  open  for  the 
removal  of  stones.  This  swinging  bolt  is  secured  to  the  case 
by  a  pin  of  just  sufficient  strength  to  hold  under  normal  con- 
ditions, and  when  undue  strain  comes  from  hard  clay,  etc.,  it 
yields,  thus  forming  a  perfect  safeguard  against  accidents  aris- 
ing from  improper  feeding.  This  "former"  is  also  heated  by 
steam,  to  facilitate  the  forming  and  sliding  of  the  clay. 

The  forming  and  finishing  part  of  the  die  (which  determines 
the  exact  breadth  and  thickness  of  the  bar  of  clay  or  the  brick) 
is  a  hard  iron  lining,  that  can  be  removed  and  renewed  in  a 
few  minutes  and  at  trifling  cost,  thus  enabling  us  to  always 
keep  our  dies  (or  moulds),  and  consequently  the  brick,  to 
standard  size. 

As  the  bar  of  clay  issues  from  the  forming-die,  it  passes 
through  a  small  chamber  filled  with  fine,  dry  sand,  which  ad- 
heres to  the  surface  of  the  brick.  The  surplus  sand  is  kept 
back  in  the  chamber  by  swinging  elastic  scrapers,  which  allow 
the  bar  to  escape  with  its  adhering  sand. 

This  sanded  surface  of  the  clay  bar  renders  the  brick,  when 
green,  much  nicer  to  handle,  prevents  them  from  sticking 
together  on  the  barrows  or  in  the  hacks,  or  on  the  drying  cars, 
and  much  improves  them  in  color  when  burnt. 

This  continuous  rectangular  bar  is  then  cut  into  brick  lengths 
by  automatic  devices  which  are  under  the  control  of  the  issuing 
clay  bar.  One  of  these  devices  is  known  as  the  spiral  cut-off, 
and  consists  of  a  thin  blade  of  tempered  steel,  secured  to  the 
periphery  of  a  drum,  in  the  form  of  a  spiral,  the  distance  be- 
tween the  blades  of  which  is  that  required  for  the  length  of  a 
brick,  and  the  projection  of  which  gradually  increases  from 
nothing  at  its  first  end  to  the  full  width  of  the  widest  brick  to 
be  cut. 

This  spiral  knife  runs  perpendicularly  in  openings  in  the 
links  of  an  endless  chain,  supported  upon  rollers,  the  chain 
being  so  formed  as  to  support  the  bar  of  clay  from  the  bottom 
and  one  edge ;  the  clay  is  thus  fully  supported  while  being 


CHAMBERS    BRICK    MACHINE.  2O5 

slowly  cut  off  by  the  long  drawing  cut  of  the  spiral  blades  in 
passing  through  the  openings  in  the  chain. 

The  distance  between  the  spiral  blades  being  uniform,  the 
lengths  of  the  brick  are  absolutely  uniform,  and  the  drawing 
cut  of  the  spiral  blade  cuts  the  end  of  the  brick  perfectly 
smooth,  and  almost  mathematically  square. 

The  speed  of  this  spiral  cutting-blade  is  controlled  by  the 
speed  of  the  clay  itself,  hence,  no  matter  how  irregular  the  flow 
of  clay  from  the  die,  the  spiral  runs  in  exact  unison  therewith, 
consequently  the  absolute  uniformity  in  the  length  of  the  brick. 

Fig.  63  shows  the  Chambers  Machine  as  constructed  up  to 
and  including  the  automatic  sander. 

Another  device  used  by  Chambers  Brothers  Company  for 
severing  the  continuously  moving  clay  bar  into  brick  lengths  is 
known  as  the  "  automatic  wire  cut-off,"  and  is  recommended  by 
the  manufacturers  for  smooth  clays  or  those  reasonably  free 
from  stones  and  gravel. 

It  consists  of  a  regulating  frame  or  table,  on  to  which  the 
clay  bar  is  carried  from  the  sander,  and  by  which  the  cut-off  is 
controlled  or  governed. 

The  belt  carrying  the  clay  bar  runs  around  a  measuring 
wheel,  which  determines  the  exact  length  the  brick  are  to  be 
cut.  . 

The  cut-off  wires  are  strained  on  steel  bows  or  springs  to  the 
proper  tension  to  cut,  and  yield  readily  to  obstructions. 

The  wires  are  carried  by  their  springs  on  a  sprocket-wheel 
over  and  through  the  clay  bar,  and  are  guided  square  by  a  cam, 
encased  in  an  oil-tight  case. 

The  partly- severed  brick  is  supported  and  held  against  the 
unsevered  bar  until  completely  severed,  when  it  is  dropped  on 
to  the  off-bearing  belt  and  promptly  carried  off,  allowing  the 
wire  to  return  above  the  bar  again  between  the  brick  and  the 
end  of  the  unsevered  bar.  Thus  the  bar  is  divided  into  uniform 
lengths  with  square  heads  and  with  all  the  smoothness  that  a 
fine  steel  wire  will  give  in  the  clay. 

The  wires  either  cut  around  the  stones  or  spring  over  them, 


206 


BRICK,  TILES    AND   TERRA-COTTA. 


CHAMBERS   BRICK.  MACHINE. 


207 


Of  THE 

UNIVERSITY 


208 


BRICK,  TILES    AND   TERRA-COTTA. 


and  run  from  morning  until  night  without  bother  or  trouble. 
Should  a  wire  break,  it  can  be  removed  at  once  without  even 
stopping  the  machine. 

Fig.  64  shows  the  Chambers  machine  as  fitted  with  the  auto- 
matic wire  cut-off.  Machines  with  this  style  of  cut-off  are 
made  of  different  capacities,  ranging  from  ten  thousand  brick 
per  day  to  one  hundred  thousand  brick  per  day  of  ten  hours. 


CHAPTER  VI. 

THE   MANUFACTURE   OF   STREET-PAVING  BRICK. 

THERE  are  three  things  of  prime  importance  upon  which  the 
successful  manufacturer  of  vitrified  brick  for  roadway  paving 
depends.  1st.  There  must  be  a  ready-made  market  at  hand, 
with  ample  shipping  facilities.  2d.  The  material  to  be  used 
for  the  making  of  the  brick  must  be  suitable  in  its  nature.  3d. 
The  material  must  be  sufficient  in  quantity  to  warrant  the  es- 
tablishment of  a  plant  of  such  a  capacity  as  to  meet  the  demand 
of  the  market. 

These  three  things  being  present,  they  make  it  possible  to 
obtain  the  capital  with  which  to  equip  and  operate  the  works, 
and  skill  in  management  and  suitable  labor  are  always  com- 
manded by  capital.  The  purchase  of  special  machinery  for 
preparing  the  material  and  for  moulding  the  same  into  brick 
form,  and  the  erection  of  artificial  dryers  and  kilns,  are  matters 
which  depend  wholly  on  the  kind  and  nature  of  the  clay,  shale 
or  other  material  to  be  worked. 

The  prime  requisites  for  a  good  paving  brick  are : 

1.  That  it  shall  have  a  vitreous  body. 

2.  That  it  shall  be  of  sufficient  toughness  to  prevent  crumb- 
ling under  the  traffic. 

3.  That  it  shall  be  free  from  pores,  a  dense  mass  which  will 
not  absorb  the  moisture,  gases  or  impurities  of  the  street  or 
atmosphere. 

To  secure  these,  the  first  essential  is  selection  of  a  suitable 
clay;  the  second,  proper  preparation;  and  the  third,  skillful 
burning,  burning  to  the  point  of  thorough  vitrifaction,  without 
risk  of  melting. 

A  description  of  the  various  clays  suitable  for  the  manufac- 
14  ( 209  ) 


2IO  BRICK,  TILES   AND   TERRA-COTTA. 

ture  of  vitrified  brick  for  roadway  paving  will  be  found  described 
under  the  head  of  CLAY  in  Chapter  II. 

PAVING-BRICK    PLANT   CONSTRUCTION. 

There  is  no  fixed  rule  which  can  be  followed  in  constructing 
paving-brick  plants.  Mr.  Eudaly,  who  has  had  a  large  exper- 
ience in  this  class  of  work,  names  the  following  general  features 
which  should  be  observed : 

First :  The  dry  pans  or  crushers  should  be  so  located  with 
reference  to  the  clay  bank  that  the  clay  can  be  dumped  to  the 
crushers,  in  this  way  avoiding  the  great  amount  of  manual 
labor  that  would  otherwise  be  required  to  elevate  the  clay  with 
shovels  to  the  hopper  of  the  crusher.  Again,  the  clay  should 
be  dumped  near  enough  to  the  crusher  so  that  no  conveying  in 
wheelbarrows  or  otherwise  is  necessary.  Of  course  this  cannot 
be  done  when  it  is  necessary  to  house  a  large  quantity  of  clay 
for  winter  use.  The  crusher  should  be  between  the  clay  bank 
and  the  pug  mill,  if  possible. 

Second :  The  pug  mills  should  be  elevated  above  the  ma- 
chinery, so  that  one  elevating  the  clay  would  carry  it  from  the 
crusher  to  the  machine. 

Third :  Need  I  mention  so  plain  a  matter  as  that  of  having 
the  dryer  and  machine  house  in  close  proximity,  and  con- 
veniently arranged,  so  that  the  brick  from  the  machine  can  be 
easily  and  quickly  put  into  the  dryer? 

Foitrth  :  Or  is  it  necessary  to  say  that  the  dryer  should  be 
conveniently  situated  in  reference  to  the  kilns? 

Fifth  :  Or  that  the  kilns  should  be  convenient  to  the  railroad 
switch  or  road? 

Yes,  it  is  necessary,  as  I  have  seen  during  the  past  season 
several  plants,  and  I  regret  to  say  some  of  them  were  new  ones 
where  these  very  simple,  and  to  most  men  plain,  necessities 
were  sadly  overlooked  or  disregarded. 

Sixth  :  The  railroad  switch  should  be  convenient  to  the  kilns 
and  the  storage  sheds.  This  is  a  matter  often  difficult  to  ar- 
range, for  the  reason  that  three  unwieldy  elements  enter  into 


MANUFACTURE   OF    STREET- PAVING   BRICK.  211 

consideration — kilns,  storage  sheds  and  railroad  cars.  Both 
the  storage  sheds  and  cars  should  be  convenient  to  the  kilns 
and  convenient  to  each  other.  These  are  requisites  hard  to' 
accommodate,  but  as  it  is,  no  doubt*  most  economical  to  load 
the  paving-brick  directly  from  the  kilns  to  the  cars,  the  cars 
should  have  the  preference  over  the  storage  sheds  as  to  posi- 
tion. This  being  the  case,  many  plants  are  arranged  so  that 
the  bottom  of  the  cars  comes  to  a  level  with  the  kiln  floor. 
This  is  done,  of  course,  by  lowering  the  railroad  switch,  which 
is  very  bad  in  winter  or  wet  weather  unless  ample  over-draining 
is  provided.  We  know  of  a  number  of  yards  where  the  natural 
lay  of  the  land  is  such  that  this  arrangement  can  be  had  with- 
out excavating  for  the  switch  track.  Now  that  the  track  is 
properly  in  front  of  the  kilns,  many  locate  the  storage  shed  be- 
yond the  switch  track,  and  by  the  use  of  strong  rough  boards 
wheel  the  brick  across  the  track  to  the  sheds.  Once  the  brick 
are  properly  hacked  under  the  sheds  along  the  switch,  they  can 
be  easily  loaded  into  the  cars.  Of  course,  the  floor  of  the 
storage  sheds  should  be  on  a  level  with  the  kiln  floor,  and 
hence  on  a  level  with  the  bottom  oi  the  cars  standing  on  the 
switch. 

Seventh  :  The  arrangement  of  dryer,  kilns  and  cars  or  storage 
sheds  should  always  be  such,  if  possible,  that  the  kilns  may  be 
emptied  at  the  opposite  end  from  that  at  which  they  are  filled 
with  the  green  brick,  for  the  reason  that  it  is  very  desirable  not 
to  have  the  brick  setters  and  loaders  in  each  other's  way.  If 
care  is  taken  at  this  point,  a  great  deal  of  annoyance  and 
trouble  will  be  avoided. 

Eighth  :  The  plant  as  a  whole  should  be  as  compact  as  pos- 
sible. I  do  not  mean  by  this  that  the  buildings  should  be 
small,  for  any  one  who  has  had  experience  knows  that  they 
should  be  large  and  roomy,  but  I  mean  that  each  and  every 
department  of  the  works  should  be  as  convenient  as  possible 
to  every  other  part  upon  which  it  is  directly  dependent. 


212  BRICK,  TILES   AND   TERRA-COTTA. 

STARTING   AND    MANAGING  A   PLANT. 

There  are  a  large  number  of  capitalists  embarking  in  the 
manufacture  of  street- paving  brick,  men  who  make  a  success  of 
their  undertakings  by  surrounding  themselves  with  the  best 
experience  and  knowledge  obtainable.  On  this  point  Mr.  Wm. 
H.  Brush,  of  Buffalo,  N.  Y.,  says : 

"There  is  no  business  pursuit  within  the  range  of  my  limited 
experience  or  knowledge  that  calls  more  imperatively  for  a  sys- 
tem than  does  the  ancient  and  honorable  calling  of  a  brick- 
maker — a  calling  whose  antiquity  is  beyond  question,  and  of 
whose  honor  and  respectability  there  is  no  need  of  defense. 
System  bears  the  same  relation  to  brick-making  that  a  rudder 
does  to  a  ship,  and  is  as  necessary.  System  is  everything, 
from  the  clay  bank  of  your  yard  to  the  first  national  bank  of 
your  native  town.  The  old  saying  that  'Money  makes  the 
mare  go'  is  true.  We  cannot  in  these  days  of  'spot  cash'  con- 
duct a  business  without  its  aid.  We  must  have  some  honest 
bona  fide  capital  besides  '  cheek,'  and  the  more  of  the  two  com- 
bined the  better,  in  order  to  make  a  success  of  brick-making. 
Capital  without  force  or  energy  to  drive  things  along  is  well 
nigh  useless.  Experience,  with  its  many  costly  lessons,  aids 
your  understanding." 

Mr.  J.  A.  Reep  says :  "  Above  all  things  have  a  good,  com- 
petent and  reliable  man  as  superintendent  or  other  manager  of 
your  works,  a  man  with  practical  experience  and  business  tact, 
one  who  can  command  the  respect  of  both  employer  and  em- 
ployes. Get  him,  and  then  make  his  situation  so  agreeable 
that  it  will  pay  him  to  stay  and  you  to  keep  him.  You  will 
find  enough  men  willing  to  serve  in  his  stead,  at  lower  wages ; 
but  it  will  be  better  for  you,  if  he  has  got  things  to  running 
smooth,  and  seems  to  have  but  little  to  do,  to  bear  in  mind 
that  if  you  change  for  a  new  and  untried  man,  with  no  qualifi- 
cations for  the  place,  that  you  and  the  new  man  both  will  be 
kept  very  busy  for  a  long  time  to  come. 

"  How  often  is  it  the  case  that  after  a  few  months  of  close 
management  and  well-directed  effort  on  the  part  of  the  man- 


MANUFACTURE   OF   STREET-PAVING   BRICK.  213 

ager,  some  member  of  the  new  company,  who  is  a  novice  in 
brick-making  in  all  its  details,  is  constrained  to  believe  that  the 
superintendent  is  an  unnecessary  adjunct  to  a  brickyard,  and 
that  they  in  particular  have  no  need  of  a  man  of  that  kind  ! 
The  hands  they  employ,  apparently  to  them,  do  not  need  him, 
and  can  get  along  without  him. 

"  The  matter  is  talked  over  and  worked  up  until,  as  a  sort  of 
trial  to  see  how  it  will  operate,  the  superintendent  is  dismissed, 
and  his  salary  is  saved.  But  at  what  cost  to  the  company ! 
The  ruin  of  one  kiln  of  brick,  which  always  quickly  follows, 
would  have  paid  the  salary  for  one  or  more  years  to  come. 
And  then  comes  not  only  one  kiln  lost,  but  several  follow  in 
quick  succession,  or  partially  so.  Trade  is  lost  that  is  hard  to 
regain.  Confidence  is  hard  to  restore  in  the  ability  of  the 
company  to  furnish  their  advertised  goods  promptly  and  of  a 
decided  good  quality,  and  for  a  time  ruin  is  imminent." 

THE  SIZE  OF  PAVING-BRICK. 

Mr.  Shea,  of  Decatur,  111.,  regarding  the  size  of  paving-brick, 
says :  "  There  are  about  as  many  varieties  in  sizes  as  there  are 
in  clays.  Different  people  make  different  sizes  of  paving-brick. 
The  question  is,  which  is  the  best  size?  I  have  come  to  the 
conclusion — and  I  think  a  majority  of  those  who  have  made  a 
study  of  the  subject  have  come  to  the  same  conclusion — that  the 
common  building-brick  size  is  not  only  the  best  size,  but  that 
it  is  the  most  profitable  size  to  make  paving-brick,  and  for  the 
following  reasons :  First,  it  is  very  much  easier  to  burn  a  small 
brick  than  a  large  one ;  next,  I  do  not  think  there  has  been  in- 
vented, as  yet,  a  kiln  that  will  burn  all  the  brick  exactly  alike. 
At  least  I  have  never  seen  one,  and  I  have  had  a  great  deal  of 
experience  with  kilns.  For  that  reason,  there  will  be  some 
waste  in  the  best  of  kilns,  and  if  you  have  the  common  build- 
ing-brick size,  you  will  see  that  the  softer  brick — those  that  are 
not  hard  enough  for  pavers — will  sell  very  readily  for  building 
purposes.  If  you  have  a  large  lot  of  common  brick  it  will  be 
necessary  to  put  your  loss  on  them  on  the  price  of  good 


214  BRICK,  TILES   AND   TERRA-CO1TA. 

paving-brick,  of  course.  Another  point  about  the  size :  It  is 
very  much  easier  to  repair  a  street,  in  case  you  have  to  make 
repairs,  to  allow  for  the  putting  down  of  pipes  for  gas  or  water, 
because  you  could  take  out  a  few  brick  and  do  the  repairing 
easily  and  replace  them.  I  think  that  would  also  be  a  good 
reason  for  adopting  the  common  building-brick  size  for  pavers." 

There  are  several  manufacturers  of  paving-brick  who  have 
discarded  the  idea  of  making  such  brick  of  building-brick  size, 
preferring  the  "block"  form.  The  majority  of  experienced 
manufacturers,  however,  agree  with  Mr.  Shea,  that  the  size  of 
the  "  pavers  "  should  be  the  size  of  the  common  building-brick 
sold  in  the  local  market  where  the  street-paving  brick  are  man- 
ufactured, as  by  adopting  that  size  it  is  possible  to  burn  them 
more  uniformly,  the  loss  will  be  less,  the  drying  better  done, 
and  the  cost  of  manufacturing  less.  A  satisfactory  roadway 
pavement  must  have  a  continuous  surface.  When  the  manu- 
facturer cuts  off  the  corners,  he  simply  cuts  off  what  it  would 
require  five  years  of  traffic  to  accomplish  on  a  vitrified  brick 
street.  So  when  completed  you  have  a  street  five  years  old, 
and  a  rough  street  at  that.  The  crude  idea  that  some  people 
have  that  the  brick  or  paver  must  have  a  round  corner,  knobs, 
lugs  and  grooves  in  it,  to  keep  the  brick  apart,  so  it  can  be 
filled  with  pitch,  concrete  or  sand,  in  order  to  get  the  required 
alignment,  is  absurd,  and  is  not  at  all  practicable. 

The  waste  brick  that  are  not  suitable  for  pavers,  in  the  man- 
ufacturing of  this  kind  of  odd-shaped  pavers,  are  thrown  in  the 
dump,  as  they  are  an  odd  size  and  shape,  and  can  not  be  used 
to  any  advantage  for  other  purposes. 

CONVEYING  AND  GRINDING  CLAY. 

Shale  clays  are  commonly  mined  by  blasting,  and  the  plastic 
clays  by  digging  or  "  throwing  "  the  face  of  the  bank,  which 
gives  a  good  mixture,  and  after  a  sufficient  quantity  of  the 
material  is  secured,  it  is  automatically  let  down  an  inclined 
plane  in  dump  cars,  attached  to  a  wire  cable  which  winds 
around  a  grooved  wheel.  By  this  arrangement,  the  car  laden 


MANUFACTURE    OF   STREET-PAVING   BRICK. 


215 


with  clay,  as  it  passes  down  the  incline,  pulls  the  empty  car  up 
to  be  refilled  at  the  bank.  When  the  dump  car  with  its  load 
of  clay  reaches  the  bottom  of  the  incline,  the  material  is  auto- 
matically discharged  from  the  car  into  a  9  foot  dry  pan,  in 
which  the  material  is  thoroughly  reduced  and  pulverized. 

FIG.  65. 


THE   DRY-PAN. 

Fig.  65  illustrates  the  dry-pan  made  by  the  Frey-Sheckler 
Co.  This  pan  is  built  in  three  sizes,  viz. :  7,  8  and  9  foot 
diameter.  For  strength  and  solidity  it  has  no  equal.  It  is 
designed  for  grinding  fire  clays,  shale,  quartz,  cement,  lime, 
flint,  sand,  spar,  ochre,  calcine,  grog,  plaster  rock,  plaster- 
paris,  bones,  coal,  or  any  hard  substances. 

This  pan    has   from    10  to  20  per  cent,   greater  screening 


2l6  BRICK,  TILES   AND   TERRA-COTTA. 

capacity  than  any  other  pan  of  same  size ;  it  is  also  balanced  so 
that  a  great  speed  can  be  obtained.  It  will  readily  be  seen  that 
additional  centrifugal  power  is  obtained  to  throw  the  material 
outward  over  the  screening  plates,  and  the  screens  are  of  such 
increased  area  that  the  reduction  is  increased  in  the  same  ratio. 

These  pans  are  built  entirely  of  iron  and  steel.  The  vertical 
shaft  has  a  hole  through  the  center  from  top  to  bottom,  through 
which  the  oil  passes  to  lubricate  the  bottom  bearing  with  unfail- 
ing regularity.  The  special  arrangement  of  the  bottom  bear- 
ing, having  an  oil  reservoir  under  and  around  it,  revolving  on 
the  hardest  chilled  plates,  with  distributing  oil  grooves,  saves 
friction,  heating  and  wear. 

Every  joint  is  planed  square,  every  hole  is  drilled,  and  each 
bolt  is  fitted  with  lock-nuts.  Each  roller  has  its  own  shaft,  the 
ends  of  which  are  provided  with  blocks  that  move  in  guides  in 
the  frames,  also  in  guides  in  the  shrouds  encircling  the  main 
shaft.  The  rollers  move  always  square  on  the  face  of  the  bed, 
whereas  if  both  rollers  are  on  one  shaft,  if  one  is  lifted,  the  other 
follows  to  some  extent,  so  that  only  the  corners  touch  the  bed. 
One  side  of  each  vertical  guide  at  the  end  of  the  roller  is  re- 
movable, which  allows  the  shaft  and  roller  to  be  taken  out  with- 
out delay.  The  ends  of  the  roller  shafts  are  supported  by 
heavy  coil  springs,  so  that  they  are  close  to  but  do  not  touch 
the  floor  plates  when  the  pans  are  empty. 

The  space  between  the  rollers  and  floor  plates  can  be  nicely 
adjusted  to  suit  each  material  by  means  of  adjusting  screws  and 
rubber  springs  in  the  frames  and  shroud,  which  encircle  the 
vertical  shaft.  The  rollers  have  deep,  hard  chilled  tires,  which 
can  be  readily  removed  from  centers  when  the  substitution  of 
new  tires  is  necessary.  The  floor  plates  and  screen  plates  are 
both  chilled. 

The  scrapers  are  hung  on  universal  joints,  so  that  they  can 
be  adjusted  in  any  direction ;  they  are  also  provided  with  inter- 
changeable chilled  face  plates,  which  render  the  wear  of  the 
scrapers  four  times  as  long  as  that  of  the  ordinary  scraper. 

These  dry-pans  are  driven  with  a  friction  clutch  pulley  48 


MANUFACTURE   OF   STRE-ET-PAVING   BRICK. 

inches    diameter,    12    inch    face;   speed,    150    revolutions    per 
minute. 

Approximate  weight  of  /-foot  pan,  21,000  pounds. 

Approximate  weight  of  8-foot  pan,  26,000  pounds. 

Approximate  weight  of  9-foot  pan,  30,000  pounds. 

This  machine  is  fully  protected  by  patents. 

FIG.  66. 


IMPROVED   TAILINGS   CRUSHER. 

Fig.  66  illustrates  the  No.  12  Improved  Tailings  Crusher 
made  by  the  Frey-Sheckler  Co. 

This  machine  is  adapted  for  reducing  the  tailings  of  shale, 
fire-clays,  or  any  refractory  or  silica  clays.  It  is  also  adapted 
for  crushing  soft  or  alluvial  clays. 

The  rolls,  20  inches  in  diameter,  26  inches  long,  are  made 
of  charcoal  chilled  iron,  with  steel  shafts  through  them.  The 
rolls  are  ground  to  a  smooth  bearing  surface  and  are  run  at 
differential  speed. 

The  clay  is  fed  into  the  rolls  by  means  of  a  vibrating  apron, 
and  the  flow  of  clay  is  evenly  regulated  by  adjusting  screws. 
This  machine  is  built  very  strong  and  rigid,  and  is  a  favorite 


218  BRICK,  TILES   AND   TERRA-COTTA. 

among  brick  manufacturers.  The  driving  pulleys  are  34  inches 
in  diameter,  12  inch  face;  speed  175  and  250  revolutions  per 
minute.  Capacity,  30,000  to  50,000  brick  per  day,  according 
to  nature  of  the  clay ;  weight,  4,765  pounds. 

This  machine  is  fully  protected  by  patents. 

From  the  dry-pan  the  ground  clay  is  conveyed  to  the  upper 
floor  of  the  factory,  where  it  is  separated,  the  fine  clay  falling 
into  a  bin  and  the  "  tailings  "  or  coarse  clay  passing  by  gravity 
back  into  the  tailings  crusher  shown  in  Fig.  66  or  into  the  dry- 
pan,  to  be  again  ground  until  it  is  reduced  to  such  a  degree  of 
fineness  as  to  allow  it  to  pass  through  the  screen  into  the  bin. 

There  is  not  much  room  for  economizing  in  the  grinding  and 
tempering  of  clay  to  be  used  in  the  manufacture  of  pavers,  as 
the  best  grade  of  such  brick  can  only  be  made  from  the  ma- 
terial which  has  been  properly  ground  and  prepared. 

Mr.  G.  H.  Brown,  of  Sioux  City,  Iowa,  says:  "The  first  step 
in  making  a  paving  brick  is  the  thorough  preparation  or  "  tem- 
pering" of  the  clay.  It  must  be  ground  fine.  I  do  not  believe 
that  a  first-class  paving  brick  can  be  made  where  there  are 
lumps  as  big  as  peas  scattered  all  through  them.  It  may  make 
a  hard  brick,  good  enough  for  sewers,  and  for  similar  purposes 
perhaps,  but  it  won't  be  a  paving  brick.  Our  own  clay  is  hard 
to  manage — what  is  known  as  refractory  clay.  We  run  it 
through  two  dry  pans  and  a  pug-mill,  but  are  dissatisfied  with 
the  texture  even  then.  The  clay  is  dug  with  a  steam  shovel, 
and  consequently  goes  into  the  pans  direct  from  the  bank.  It 
is  damp,  very  tough,  and  inclined  to  be  sticky  and  to  pack 
under  the  '  ploughs '  in  the  pans.  The  finest  paving  brick  I 
ever  saw  in  my  life,  bar  none,  are  being  made  to-day  at  the 
Northwestern  Sewer  Pipe  Works  at  Sioux  City,  where  the  clay, 
after  going  through  a  dry  pan,  is  put  through  two  wet  pans, 
and  that,  to  my  mind,  is  a  solution  of  the  question — provided 
that  sufficient  capacity  can  be  obtained  by  means  of  wet  pans. 
That  is  a  point  which  I  am  not  competent  to  determine,  but 
one  that  the  makers  of  wet  pans  would  do  well  to  study,  and 
perhaps  improve  upon." 


MANUFACTURE    OF   STREET- PAVING   BRICK.  219 

MOULDING  AND  PRESSING. 

On  this  point,  Mr.  G.  H.  Brown  speaks  as  follows  :  "  Having 
got  your  clay  well  '  tempered/  the  next  thing  is  to  pass  it 
through  a  machine  which  will  compress  the  utmost  amount  of 
clay  into  a  given  space.  Your  bar  of  clay  must  be  as  dense, 
solid  and  hard  as  you  dare  to  work  your  machinery.  A  soft  bar 
of  clay  means  a  great  shrinkage  in  the  drying  and  burning,  and 
an  exaggerated  change  in  the  size  of  the  brick  in  passing  from 
the  green  to  the  dry  state  is  sure  to  entail  more  or  less  check- 
ing and  warping,  and  the  result  be  a  weak  or  distorted  brick, 
to  say  nothing  of  the  difficulty  of  handling,  and  a  greater  per- 
centage of  loss.  Everybody  knows  there  is  a  vast  difference 
in  the  shrinkage  of  different  clays ;  but  in  my  judgment,  when 
you  are  making  a  stiff-mud  brick,  make  it  stiff  as  you  can,  both 
by  heaviest  possible  pressure  in  the  machine,  and  by  avoiding 
too  lavish  use  of  water." 

If  the  clay  is  to  be  molded  into  brick  by  a  stiff-clay  brick 
machine,  by  which  class  of  machines  nearly  all  paving-brick 
are  now  produced,  it  passes  by  gravity  from  the  clay-bin  to  the 
hopper  of  the  brick  machine,  and  is  tempered  and  molded 
into  brick,  which  are  uniformly  end-cut  after  the  bar  of  clay 
reaches  the  cutting  table. 

Soft-clay  brick  machines  are  used  in  molding  some  clays, 
and  side-cut  stiff-clay  brick  machines  are  also  sometimes  em- 
ployed. 

If  the  clay  is  to  be  molded  into  brick  by  any  of  the  ordinary 
forms  of  sewer-pipe  machines,  it  passes  from  the  clay-bin  by 
gravity  through  a  chute  into  a  7-foot  wet,  or  tempering  pan, 
where  the  different  clays  are  thoroughly  mixed  and  incorpo- 
rated into  a  plastic  mass  by  the  addition  of  a  sufficient  quantity 
of  water.  After  being  thus  made  plastic,  the  tempered  clay,  on 
being  discharged  from  the  wet-pan,  is  again  elevated  into  the 
second  story  of  the  building  and  discharged  into  an  automatic 
feeder,  which  feeds  the  material  into  a  sewer-pipe  press.  The 
brick  come  from  the  press  usually  in  eight  streams  of  suitable 
width  and  thickness  for  paving-brick,  and  are  cut  off  into  suit- 
able lengths. 


220  BRICK,  TILES   AND   TERRA-COTTA. 

Paving  blocks  can  be  molded  by  either  a  stiff  clay  brick 
machine  or  a  sewer  pipe  press.  If  the  blocks  are  being 
molded  on  a  pipe  press,  the  clay  passes  through  a  die  which 
allows  only  six  streams  to  be  emitted  from  the  press,  and  these 
blocks  are  cut  into  9  inch  lengths,  and  it  is  common  to  make 
20,000  of  them  in  one  day  of  ten  hours. 

It  has  not  heretofore  been  usual  to  re-press  paving  brick  made 
on  stiff- clay  brick  machines.  Some  manufacturers  of  paving 
brick  do,  however,  re-press  them,  and  it  pays  to  do  so,  as  the 
brick  by  re-pressing  acquire  a  greater  density.  The  brick  in 
this  way  become  non-absorbent,  and  are  of  uniform  size  and 
finish.  Such  brick  present  a  uniform  surface  for  the  passage  of 
vehicles  when  the  brick  are  laid  in  the  roadway.  The  liability 
to  flake  or  spall  is  also  lessened  by  re-pressing. 

The  time  has  come  when  manufacturers  of  brick  and  blocks 
intended  to  be  used  for  the  paving  of  public  roadways  can  no 
longer  afford  to  put  such  brick  upon  the  market  without  re- 
pressing them.  The  only  reason  why  paving  brick  and  blocks 
have  not,  in  all  cases,  been  re-pressed  in  the  past,  is  the  fact 
that  manufacturers  of  this  class  of  clay  wares  have  been  so 
crowded  with  orders  that  they  have  been  enabled  to  put  upon 
the  market  large  quantities  of  brick  and  blocks  which  ought 
never  to  have  left  the  yards  where  they  were  made.  The  rapid 
extension  which  is  now  going  on  in  both  the  construction  of 
new  plants  devoted  to  the  manufacture  of  street  paving  brick 
and  in  the  enlargement  of  the  capacities  of  such  plants  already 
in  operation,  make,  in  a  great  measure,  the  shipment  of  inferior 
paving  brick  and  blocks  in  the  future  almost  impossible — the 
reason  of  this  being  that  there  is  now  a  more  general  and 
thorough  knowledge  concerning  the  qualities  which  are  neces- 
sary to  be  possessed  by  vitrified  brick  and  blocks,  if  they  are 
to  be  used  for  the  paving  of  roadways.  A  paving  brick,  if  it  is 
properly  made,  should  be  so  dense  as  to  make  it  impossible  for 
such  a  brick  to  absorb  even  an  ounce  of  moisture.  Such  a 
brick  must,  in  addition  to  great  density,  be  true  in  shape,  hav- 
ing good  corners,  heads,  faces  and  arrises  in  order  that  .the 


MANUFACTURE   OF   STREET-PAVING   BRICK.  221 

brick,  when  laid  in  the  roadways,  shall  lie  close  to  the  neigh- 
boring brick  and  present  a  smooth,  uniform  surface.  There  is 
no  possible  way  by  which  these  desirable  qualities  can  be  im- 
parted to  a  paving  brick,  except  by  re-pressing. 

Paving  brick,  with  of  course  fusible  toughening  elements, 
are  properly  prepared  for  the  greatest  constructive  element,  fire, 
by  pressure ;  hence,  as  a  sequence,  their  absorbent  conditions 
are  practically  wiped  out. 

Common  building  brick  generally,  on  account  of  their  uses, 
are  not  subjected  to  great  pressure ;  hence  absorption  rules  at 
from  ten  to  seventeen  per  cent. 

What  gold  and  silver  are  to  commerce  and  the  arts,  what 
chemistry  is  to  life ;  what  order  is  to  nature,  so  is  pressure  to 
all  paving  brick  products. 

The  Chicago  Roadway  Paving  Ordinance,  which  was  recently 
passed,  provides  that  all  brick  used  for  paving  purposes  in  that 
city  "  shall  be  of  the  kind  known  as  re-pressed  brick,  and  shall 
be  re-pressed  to  the  extent  that  the  maximum  amount  of  mate- 
rial is  forced  into  them." 

DRYING. 

The  brick  after  being  molded  by  the  stiff- clay  brick  ma- 
chine or  pipe  press,  or  which  have  been  re-pressed  in  the  man- 
ner described,  are  loaded  on  trucks  and  carried  to  the  drying 
tunnels.  Of  course  brick  intended  for  use  in  street-paving  can 
be  dried  in  any  of  the  ways  in  which  brick  made  by  the  stiff- 
clay  process  are  commonly  dried.  In  the  best  forms  of  arti- 
ficial dryers  the  brick  dry  without  cracking,  and  are  in  as  good 
a  condition  for  setting  into  the  kiln  as  it  is  possible  to  get  them 
even  if  they  were  dried  in  the  open  air.  The  advantages  of 
artificial  drying  are  many  and  are  well-known :  the  cost  of 
building  and  maintaining  sheds  is  saved ;  the  loss  from  rain  or 
floods  when  the  brick  are  dried  in  sheds  is  also  saved ;  rainy 
and  freezing  weather  do  not  cause  interruptions  and  loss  of 
time ;  the  works  can  be  operated  continuously  throughout  the 
year;  time  and  fuel  are  saved  in  water-smoking,  which  is  the 


222  BRICK,  TILES   AND   TERRA-COTTA. 

same  as  increasing  kiln  capacity,  and  there  Lre  no  delays  in 
waiting  for  dry  brick.  Most  paving  brick  clays  can  be  dried 
in  twenty-four  hours ;  some  clays  are  so  tender,  however,  that 
a  longer  drying  and  hence  a  greater  drying  capacity  are  nec- 
essary than  with  the  strong,  rapid-drying  clays. 

BURNING. 

After  the  brick  have  been  exposed  to  the  action  of  the 
heat  for  a  sufficient  length  of  time  in  the  drying  departments 
of  the  factory  they  are  conveyed  to  the  kilns  on  the  cars  on 
which  they  are  dried,  or  are  wheeled  and  set  for  burning  in 
down-draft  kilns.  The  "  water-smoking "  or  steaming  of  the 
brick  requires  about  three  days,  after  which  the  temperature  of 
the  kiln  is  gradually  raised  for  24  hours,  and  then  for  48  hours 
additional  the  brick  are  given  heavy  and  full  fires  in  order  to 
thoroughly  vitrify  the  material.  The  cooling  of  the  kiln  is 
done  slowly,  the  draft  being  checked  after  the  final  fires.  The 
brick  are  drawn  from  the  kiln  by  loading  them  upon  wheel- 
barrows, on  which  they  are  usually  run  over  a  gangway  di- 
rectly into  the  cars  which  are  to  convey  them  to  some  other 
city  or  town.  The  switch. from  the  main  track  of  the  railroad 
should  allow  the  cars  to  approach  close  to  the  burning  kilns, 
which  should,  if  possible,  be  so  built  that  the  kiln  floors  are  on 
a  level  with  the  top  of  the  cars. 

The  use  of  crude  oil  for  the  burning  of  vitrified  brick  is  a 
great  advance  over  the  employment  of  coal.  Crude  oil  is  more 
economical  in  many  locations  than  coal,  and  more  intense  and 
steadier  heats  can  be  had  with  oil  than  with  coal,  and  the  vitri- 
fication of  the  clay  is  more  thorough  with  oil  than  with  coal ; 
hence  a  better  and  more  satisfactory  product  is  secured.  Fuel 
gas  is,  however,  the  coming  fuel  for  burning  not  only  street 
paving-brick,  but  all  other  forms  of  brick  made  from  refractory 
or  semi-refractory  clays.  As  a  rule,  street  paving-brick  require 
to  be  fired  from  twenty-  four  to  thirty-six  hours  longer  at  the 
highest  heat  attainable  in  ordinary  down-draft  kilns,  than  do 
hard  building-brick  made  from  the  same  clay.  The  brick  for 


MANUFACTURE    OF   STREET- PAVING   BRICK.  223 

street  paving  purposes  must  be  slowly  cooled,  so  as  to  anneal 
them  and  impart  the  desired  toughness,  without  which  the  brick 
are  not  salable. 

The  question  is  often  asked:  "All  things  being  equal,  what 
is  the  difference  in  the  cost  of  burning  paving-brick  and  the 
common  hard  building- brick?" 

Mr.  E.  M.  Pike,  of  Chenoa,  111.,  has  answered  this  question 
as  follows ; 

"  With  our  clay  fired  up  to  the  point  which  we  denominate 
good  hard  brick  (there  is  a  chance  of  variation  as  to  what  a 
hard  brick  is),  brick  that  would  do  for  sidewalk,  or  the  face  of 
a  building,  or  for  side  walls — we  hold  this  same  brick  about 
twenty-four  hours  after  passing  from  this  time.  With  our  clay 
the  brick  .will  vitrify ;  with  other  clay  you  might  hold  the  brick 
for  forty-eight  hours  and  they  would  not  vitrify.  The  question 
is,  what  is  the  difference  in  the  cost  of  burning  paving-brick 
and  common  hard  building-brick?  I  would  say  that  the  differ- 
.ence  in  cost  is  the  cost  of  the  fuel  it  takes  to  run  that  clay  from 
the  point  necessary  to  burn  building-brick  to  the  point  of  vitri- 
fication, adding  the  cost  of  the  men  it  takes  to  fire  the  whole 
kiln  from  the  hard  building-brick  point.  That  would  be  our 
expense. 

"We  finish  the  kiln  of  the  common  hard  building-brick  at 
the  point  of  white  heat,  a  heat  that  resembles  the  electric  light. 
We  continue  the  fires  and  continue  that  heat  right  along.  That 
white  heat  is  as  hot  as  we  can  make  it.  We  continue  that  heat 
for  about  twenty  hours,  and  at  the  end  of  that  time  our  brick 
are  vitrified." 

In  giving  the  result  of  his  experience  regarding  the  manner 
of  burning  street  paving-brick,  Mr.  A.  O.  Jones,  of  Zanesville, 
Ohio,  says : 

"The  best  results  in  burning,  so  far  as  my  knowledge  goes, 
are  from  that  class  of  kilns  known  as  the  '  down-draft/  for  with 
these  kilns  you  can  retain  the  heat  and  allow  your  brick  to 
anneal  and  toughen." 

In  Atchison,  Kan.,  down-draft  kilns   are   used   for  burning 


224  BRICK,  TILES   AND   TERRA-COTTA. 

street  paving-brick,  and  this  form  of  kiln  is  largely  used  by 
paving-brick  manufacturers. 

At  Sioux  City,  Iowa,  and  at  Beatrice,  Neb.,  continuous  kilns 
are  used  for  the  burning  of  paving-brick. 

Mr.  H.  Dawson,  Sr.,  of  Springfield,  111.,  in  speaking  of  the 
burning  of  these  brick  says : 

"  In  the  first  place  it  is  quite  necessary  to  have  the  right  kind 
of  a  kiln  to  burn  with ;  for  a  vitrified  brick  the  kiln  should  not 
be  too  high  nor  too  wide,  and  I  do  not  think  you  can  burn 
successfully  with  an  up  or  down  draft  kiln  alone.  It  is  neces- 
sary to  have  up  and  down  draft  combined  to  get  from  eighty  to 
ninety-five  per  cent,  of  good  hard  top  brick.  I  do  not  think  it 
advisable  to  set  them  more  than  thirty  brick  high,  as  too  much 
weight  is  apt  to  press  them  out  of  shape.  We  know  that  clays 
vary  a  great  deal,  but  I  claim  that  lots  of  time  be  taken  in 
water-smoking,  and  then  heat  up  slowly  till  you  get  it  to  the 
right  pitch  and  then  keep  it  there.  When  the  kiln  has  begun 
to  settle,  it  is  very  necessary  that  it  should  not  be  allowed  to 
stop.  For  the  first  two  days  we  do  not  let  it  settle  more  than 
one  inch  in  every  twelve  hours ;  after  that  the  kiln  is  well  heated 
through  and  settles  faster;  we  call  fifteen  inches  a  good  settle 
for  our  clay.  After  you  find  your  kiln  has  a  good  settle  and 
you  think  there  isn't  a  soft  brick  in  it,  burn  it  twenty-four  hours 
longer.  Of  course  I  do  not  mean  that  exactly,  but  you  can  do 
more  harm  by  closing  a  kiln  too  soon  than  by  burning  it  too 
long;.  I  am  a  brick  man,  and  expect  to  make  my  living  at  that 
business  as  long  as  I  live,  and  the  more  brick  I  sell  the  better  I 
like  it ;  but  I  do  not  want  anything  put  into  our  streets  and 
roads  other  than  a  good,  tough,  well  vitrified  brick,  that  will 
last  from  fifty  to  one  hundred  years  on  an  ordinary  travelled 
road,  without  any  repairing." 

Mr.  G.  H.  Brown,  of  Sioux  City,  Iowa,  on  the  subject  of 
burning  paving  brick  says : 

"  We  now  come  to  the  final  stage,  viz.,  the  burning ;  said  to 
be  the  most  important  of  all  the  various  steps  in  making  a  pav- 
ing brick.  For  my  part  I  think  one  step  is  just  as  important 


MANUFACTURE   OF   STREET-PAYING    BRICK.  225 

as  another.  You  may  get  a  first-class  burn  on  a  poorly  made 
brick  out  of  poor  material,  and  yet  you  won't  have  a  paving 
brick.  The  burning,  I  think,  is  probably  the  most  difficult 
part  of  the  business,  but  with  proper  care  and  experience  there 
is  no  need  of  throwing  away  money  and  time  on  bad  burns,  al- 
though the  first  requisite  towards  a  good  burn  is  a  well  built 
down-draft  kiln.  My  advice  to  one  about  to  build  a  kiln  for 
burning  paving  brick  would  be:  i.  Build  a  down-draft  kiln. 
2.  Don't  be  afraid  of  spending  an  extra  dollar%or  so  in  buying 
fire-brick  for  lining;  they  will  pay  big  dividends.  3.  Clamp 
your  kiln  in  the»very  best  manner;  if  you  produce  a  bona-fide 
paving  brick,  your  kiln  will  need  strong  bracing.  4.  Put  a 
double  crown  on  your  kiln,  two  courses  of  brick,  lower  course 
8  inches,  upper  course  4  inches. 

Mr.  W.  E.  Eudaly,  of  Cincinnati,  Ohio,  says:  "A  paving 
brick  should  be  burned  thoroughly  hard  and  to  that  condition 
wrhere  it  will  be  as  tough  as  it  is  possible  to  make  it,  and  it  should 
not  be  burned  beyond  that  point.  Now  you  may  call  that  vitri- 
fication, but  that  is  the  condition  in  which  we  want  it,  a  condi- 
tion in  which  it  will  stand  the  greatest  number  of  blows  ;  a  brick 
burned  until  it  will  stand  the  greatest  number  of  blows.  It  is 
not  a  question  of  crushing ;  it  is  a  question  of  blows  and  absorp- 
tion ;  and  you  will  find  the  journals  throughout  the  United 
States  which  are  giving  this  question  a  great  deal  of  attention 
have  come  down,  many  of  them,  to  these  two  tests,  of  the 
question  of  blows,  of  the  strikes  they  will  stand,  and  the  amount 
of  water  the  brick  will  absorb,  and  those  are  vital  questions  in 
paving  brick." 

In  speaking  of  the  subject  of  burning  paving  brick,  Mr.  D. 
W.  Stookey  says : 

"  Down-draft  kilns  seem  to  be  best  adapted  to  burning  this 
class  of  clay  goods,  as  well  as  many  others.  Two  points  of  ad- 
vantage of  down-draft  kilns  are  of  so  much  importance  that 
they  generally  hold  the  position  of  first  place  in  the  minds  of 
the  manufacturers  of  the  heavier  classes  of  clay  goods.  One 
of  these  advantages  is  the  uniformity  with  which  the  heat  may 


226  BRICK,  TILES   AND   TERRA-COTTA. 

be  distributed  throughout  the  kiln,  and  the  other  is,  because  the 
ware  that  is  heated  most  and  that  may  become  soft  from  the 
heat  and  liable  to  change  its  form  under  pressure  is  upon  the 
top  of  the  kiln  and  is  subjected  to  but  little  pressure. 

"  In  up-draft  kilns  the  parts  that  are  hottest  are  in  the  bottom 
and  must  sustain  the  weight  of  all  above  when  the  kiln  is  heated 
to  the  degree  necessary  to  fuse  the  particles  together  and 
vitrify  all  that  is  verifiable.  The  pressure  to  which  the  lower 
brick  are  subjected  by  the  superimposed  brick  will  very  likely 
cause  many  of  them  to  stick  or  weld  firmly  together,  and  many 
will  be  badly  distorted. 

"To  the  manufacturer  of  paving  brick  the  subject  of  fuel  for 
burning  the  kilns  is  one  of  interest,  and  to  which  much  thought 
and  speculation  are  given.  Of  the  four  kinds  of  fuel  in  use, 
wood,  coal,  oil  and  gas,  it  may  be  said  that  any  of  them  will 
produce  the  necessary  heat.  The  function  of  a  fuel  is  to  gene- 
rate heat,  and  it  probably  matters  but  little  in  the  end  whether 
the  brick  have  been  burned  by  heat  produced  from  one  or  an- 
other. Heat  is  heat,  and  nothing  else,  whether  it  is  generated 
in  one  way  or  another ;  whether  by  mechanical,  physical  or 
chemical  agencies. 

"  Since  the  draft  is  from  the  furnaces  through  the  ware  in 
the  kiln,  and  the  gaseous  products  of  combustion,  with  all  else 
carried  by  the  draft  pass  in  contact  with  the  ware  to  be 
burned,  it  is  probable  that  the  color  of  the  burned  goods  will 
be  somewhat  affected  by  the  particular  fuel  used.  The  prin- 
ciples involved  in  producing  a  salt  glaze  teach  that  chemical 
action  may  take  place  upon  the  outside  of  the  ware  by  the  in- 
fluence of  some  of  the  substances  carried  into  the  kiln  by  the 
draft ;  but  this  action  is  so  slightly  different  for  different  fuels 
that  it  need  not  be  considered  by  the  manufacturer  of  paving 
brick. 

"There  are  local  influences  that  bear  upon  the  circumstances 
of  each  particular  manufacturer,  and  these  must  be  taken  into 
consideration  in  the  selection  of  fuel  suited  to  each  case.  It  is 
common  to  see  in  print  arguments  and  testimonials  based  upon 


MANUFACTURE   OF   STRE-ET-PAVING   BRICK.  227 

experience  in  favor  of  this  or  that  kind  of  fuel,  and  these  are 
often  valuable  and  worthy  of  consideration  in  the  comparison 
of  different  fuels ;  but,  as  stated  above,  each  one  must  select 
that  kind  best  adapted  to  his  peculiar  circumstances.  This 
stated  in  another  way  means  that  each  one  must  select  that 
fuel  with  which  he  can  burn  his  kilns  with  the  least  expense. 

"  It  may  be  true  that  some  are  more  easily  handled  than 
others,  or  that  they  will  sustain  a  uniform  heat  with  less  atten- 
tion ;  that  they  are  more  cleanly ;  they  may  have  this  or  that 
argument  in  their  favor ;  but  the  one  idea  to  be  constantly  kept 
in  mind  is,  which  one  will  burn  a  given  amount  of  brick  satis- 
factorily with  the  least  expense.  Brick  manufactories  are  ope- 
rated as  money-making  establishments,  and  the  money  made  is 
the  difference  between  the  expense  and  the  income.  The  man- 
ager who  adopts  this  or  that  kind  of  fuel  for  burning  his  kilns 
because  it  is  the  latest  '  fad,'  because  it  is  more  cleanly  or  more 
convenient,  when  he  could  burn  his  brick  satisfactorily  with  less 
expense  by  using  some  other  kind  of  fuel,  has  lost  sight  of  the 
object  sought  in  the  establishing  and  operation  of  the  plant.  If 
the  kilns  can  be  burned  with  coal-§lack  or  cord-wood  for  less 
money  than  with  natural  gas,  the  burner  must  be  denied  the 
luxury  and  covenience  of  using  gas. 

"  In  considering  the  expense  of  burning,  the  cost  of  the  ne- 
cessary outfit  must  be  taken  into  consideration.  With  cord- 
wood,  the  outfit  may  consist  of  a  pair  of  leather  mittens  and  a 
long  fire-hoe,  costing,  all  told,  a  dollar  and  a  half. 

"With  coal,  the  necessary  apparatus  may  be  a  few  rough 
boards,  a  shovel,  an  iron  poker,  with  a  wheel-barrow  added 
in  some  cases.  With  natural  gas,  a  system  of  pipes  and 
'appurtenances  thereto,'  are  required,  and  in  order  to  burn 
crude  oil  successfully,  an  elaborate  outfit,  consisting  of  tanks, 
pipes,  pumps  and  burners,  to  which,  in  some  instances,  must 
be  added  a  steam  generating  outfit,  and  in  others,  the  steam 
generator  with  an  engine  and  air-compressing  attachment. 

"  Experiment  may  have  demonstrated  that  a  certain  number 
of  gallons  of  oil  are  equal  to  a  ton  of  coal  in  producing  heat, 


228  BRICK,  TILES   AND   TERRA-COTTA. 

and  that  the  cost  of  the  oil  is  something  less  than  that  of  the 
coal,  and  yet  the  argument  may  be  in  favor  of  the  coal,  be- 
cause of  the  necessary  expense  of  the  outfit  to  be  used,  in  order 
that  the  oil  may  be  burned  successfully. 

"  It  must  be  borne  in  mind  that  this  matter  will  depend,  in  a 
great  measure,  upon  the  amount  of  fuel  to  be  used  by  the  plant. 
If  the  difference  in  the  first  cost  is  only  slightly  in  favor  of  the 
oil,  it  would  not  be  profitable  for  a  plant  of  small  capacity  to 
abandon  the  use  of  coal  and  substitute  oil ;  but  if  the  consump- 
tion is  large  it  may  be  that  the  small  difference  in  cost  will,  in 
the  end,  amount  to  more  than  the  extra  expense  of  the  outfit 
for  burning  oil. 

"The  idea  of  producing  the  most  goods  for  the  least  money 
should  be  constantly  kept  in  mind,  and  that  fuel  should  be  used 
which  will  burn  the  kilns  and  produce  satisfactory  brick  for  the 
least  money.  Just  so  soon  as  the  manager  of  a  manufactory 
begins  to  introduce  plans  and  systems  because  of  their  conve- 
nience, style,  or  appearance,  while  they  incur  additional  ex- 
pense over  others  that  produce  as  good  good-s,  just  so  soon  he 
ceases  to  obtain  the  best  results  and  the  greatest  possible  divi- 
dends for  the  stockholders  or  profits  for  the  individual  propri- 
etor, as  the  case  may  be. 

ANNEALING. 

"  Toughness  is  one  of  the  essential  characteristics  of  a  good 
paving  brick.  It  rests  very  largely  with  the  burner  whether 
or  not  the  brick  from  his  kilns  are  tough  or  brittle,  True,  the 
proper  kind  of  clay  must  be  used,  for  it  is  not  to  be  asked  of 
the  burner  that  he  will  produce  good  tough  brick  unless  the 
brick  given  him  to  be  burned  are  made  of  clay  selected  be- 
cause it  contained  the  elements  necessary  to  make  the  required 
brick  if  it  be  properly  handled.  Yet  so  much  does  proper 
management  of  the  kiln  influence  the  toughness  of  the  brick 
that  the  success  of  the  enterprise  rests  upon  the  skill  of  the 
burner  in  annealing  the  brick,  and  thus  giving  them  the  neces- 
sary toughness.  The  best  of  clay  may  be  selected,  the  most  im- 
proved machinery  employed,  the  best  methods  of  management 


MANUFACTURE    OF   STREET-PAVING   BRICK.  2 29 

adopted,  the  brick  may  be  carefully  dried  and  go  into  the  kiln 
without  a  crack  or  check,  and  yet  improper  management  of  the 
kiln  at  the  time  of  closing  may  make  the  brick  rotten,  dead, 
shaky,  checked,  cracked,  and  wholly  unfit  for  the  purpose  for 
which  they  were  intended. 

"When  the  kiln  has  been  properly  burned  and  the  burner 
pronounces  it  finished,  the  process  of  annealing  begins. 

"  The  one  principle  involved  or  end  to  be  attained  is  slow 
cooling. 

"  Every  observing  burner  has  noticed  that  pieces  taken  from 
the  kiln  while  red  hot  and  cooled  rapidly  in  the  air  or  in  water 
present  a  cracked  and  crystallized  appearance  upon  being  frac- 
tured, and  that  they  are  easily  broken  and  are  devoid  of  the 
metallic  ring  that  is  so  desirable.  Annealing  is  a  process  that 
is  arranged  for  by  the  last  acts  of  the  burner  before  leaving  the 
kiln.  It  is  in  no  way  performed  during  the  firing  of  the  kiln, 
the  raising  of  the  heat  nor  the  holding  of  the  temperature 
while  the  heat  is  being  driven  through  the  kiln,  b'ut  is  strictly 
an  act  of  cooling. 

"  It  is  well  known  that  the  particfes  of  a  body  change  their 
positions  somewhat  during  the  expansion  attendant  upon  heat- 
ing. If  the  body  is  slowly  cooled  the  particles  may  return  to 
their  former  position  of  stability,  but  if  cooled  rapidly,  they  are 
arrested  in  the  positions  that  are  more  or  less  strained. 

"  There  is  a  constant  tendency  while  in  this  strained  state  to 
change  position,  just  as  a  strained  spring  or  bow  tries  to  return 
to  its  original  position.  A  blow  or  shock  tends  to  shatter  the 
piece  by  breaking  the  tie  at  some  point  and  thus  destroying 
the  equilibrium.  Glass  manufacturers  recognize  this,  and  by 
annealing,  which  consists  in  re-heating  and  cooling  slowly, 
allow  the  particles  to  assume  positions  less  strained  and  more 
stable,  and  consequently  the  glass  is  more  tough  and  not  so 
easily  broken. 

"  This  strained  state  of  the  particles  of  a  body  that  has  been 
rapidly  cooled  and  the  brittleness  attending  may  be  made 
clearer  to  the  mind  by  considering  the  conditions  that  exist  in 


230  BRICK,  TILES   AND   TERRA-COTTA. 

a  bow  that  is  bent  or  a  spring  that  is  strained.  When  the  strain 
is  carried  to  the  limit,  it  is  observed  that  just  before  breaking 
the  spring  or  bow  reaches  a  hard,  stiff  condition  and  seems  to 
stop  bending,  and,  as  it  were,  tries  to  resist  further  flexure,  as  if 
it  knew  that  to  go  farther  would  be  fatal. 

"  Now,  this  is  the  condition  of  the  particles  of  the  brittle  body 
that  has  been  cooled  rapidly.  If  the  cooling  process  has  been 
too  sudden,  the  body  cracks,  as  seen  in  the  tile  or  brick  that 
has  been  taken  from  the  fire  and  cooled  quickly  in  the  air  or 
in  water.  When  the  bow  has  reached  the  limit,  it  is  in  a  condi- 
tion that  it  may  be  broken  by  forcing  it  a  little  farther,  it  is  in 
a  brittle  state.  Whereas,  if  it  is  not  bent  at  all,  but  is  in  its 
normal  position,  it  may  be  said  to  be  tough,  and  may  be  bent 
considerably  in  any  direction  without  breaking.  In  cooling  an 
object  slowly,  the  particles  are  allowed  to  assume  their  normal 
positions  and  are  at  ease,  and  the  object  may  be  said  to  be 
tough.  If  cooled  rapidly,  the  particles  are  arrested  in  a 
strained  condition,  and  it  may  break  if  forced  a  little  farther, 
that  is,  it  is  brittle." 

METHODS  EMPLOYED  BY  VARIOUS  MANUFACTURERS  OF  PAVING  BRICK. 

Mr.  Beattie  says :  "  The  brick  that  we  are  making  in  Atchi- 
son,  Kansas,  is  made  out  of  a  blue-colored  shale  that  is  very 
hard.  We  have  to  use  dynamite  to  blast  it.  The  manner  in 
which  we  became  engaged  in  that  industry  I  can  say  was  by  the 
Galesburg  people,  four  or  five  years  ago,  sending  some  brick 
out  to  Atchison  to  pave  a  street.  Some  of  us  who  had  seen 
the  brick  became  interested  in  the  industry,  and  took  our  clays 
and  had  them  tested,  which  tests  proving  satisfactory,  we 
entered  into  the  manufacture  of  brick.  But  to  continue,  as  to 
the  manner  in  which  we  are  making  the  brick,  we  use  a  dry- 
pan,  and  have  a  pug-mill  and  stiff-clay  machine. 

"  So  far  as  my  experience  goes,  the  best  paving  brick  I  have 
seen  is  made  by  the  stiff-clay  process.  I  am  not  interested  in 
any  machines  or  anything  of  that  kind ;  I  do  not  care  the  snap 
of  my  finger  for  any  of  them  ;  but  close  to  where  I  live  there  was 


MANUFACTURE   OF   STREET-PAVING   BRICK.  231 

an  effort  made  to  try  to  make  street  paving  brick  by  the  dry- 
clay  process  that  was  a  dismal  failure ;  out  of  the  same  mate- 
rial good  brick  are  now  made  by  the  stiff-clay  method  of  man- 
ufacture. There  may  be  clays  that  will  make  brick  by  the  dry 
method,  and  which  will  do  for  paving,  but  for  my  part  I  have 
not  seen  them  yet. 

"  I  would  not  make  the  corners  of  paving  brick  entirely 
square,  but  a  very  little  round  at  the  edge,  not  so  much  as 
most  men  making  brick  give  it.  Where  there  is  too  much  of  a 
round  there  is  a  chance  for  the  wheels  of  passing  vehicles  to 
grind  continually  on  the  edges  of  the  brick." 

Mr.  A.  O.  Jones,  of  Zanesville,  O.,  says :  "  As  to  my  ideal 
mode  of  making  the  best  paving  brick  I  shall  refrain  from  the 
attempt  to  mention,  but  among  the  methods  of  manufacture  in 
use  in  Ohio  is  that  employed  in  preparing  the  clay  for  the 
manufacturing  of  sewer  pipes.  After  the  clot  or  glut  brick  is 
formed  it  is  then  re-pressed,  for  unquestionably  this  densities 
the  body.  Re-pressing  takes  a  little  more  fuel  for  burning,  but 
it  adds  greatly  to  the  lasting  qualities  of  the  brick.  It  also 
gives  it  a  finished  look.  Good  workmanship,  and  then  add  to 
this  perfect  burning,  for  this  is  of  the  most  vital  importance, 
and  the  result  is  a  good  paver." 

The  Grape  Creek  Clay  Company,  of  Grape  Creek,  111.,  uses 
a  shale  clay  which,  when  freshly  mined,  resembles  rock.  It  is 
first  subjected  to  heavy  crushers,  put  through  enormous  rollers, 
ground  dry,  and  elevated  to  a  revolving  pan,  when  two  massive 
rollers  running  in  opposite  directions  grind  the  shale  to  an  im- 
palpable powder,  and  subject  it  to  a  sifting  process.  It  is  again 
ground  in  a  gang  mill,  made  into  the  shape  desired.  (They 
make  three  sizes  of  blocks — 4x4x12  inches,  4x5x12  inches, 
4x6x12  inches.)  The  blocks,  after  being  molded,  are  partially 
dried,  then  subjected  to  an  intense  pressure,  then  placed  on 
racks  to  dry.  In  burning,  the  heat  is  raised  gradually  and 
cooled  off  slowly,  by  which  means  the  material  becomes  thor- 
oughly annealed,  and  the  result  is  a  brick  tougher  than  granite. 

Messrs.  Stewart  &  Collins,  of  Hastings,  Neb.,  take  a  rough 


232  BRICK,  TILES   AND   TERRA-COTTA. 

clay  from  the  bank  and  run  it  through  a  disintegrator  and  pug- 
mill,  which  reduces  it  to  dust,  and  pug  it  to  a  stiff  mud,  issuing 
it  through  the  die  of  a  stiff-clay  brick  machine,  which  automat- 
ically delivers  the  brick  upon  the  pallet  hard,  smooth  and 
straight  cut,  at  the  rate  of  from  35,000  to  40,000  per  day  of 
ten  hours. 

Their  clay  bank  stands  thirty  feet  deep,  and  is  above  the 
track  where  it  is  loaded,  being  a  solid  mass  consisting  of  an 
equal  mixture  of  iron,  shale  and  fire-clay.  The  brick  made  is 
of  standard  size,  and  when  burned  weighs  six  pounds.  They 
use  the  portable  hack,  the  track  system  exclusively.  The  clay 
will  dry  in  sun  or  wind.  They  have  had  no  cracked  brick 
whatever,  and  use  a  common  up-draft  kiln,  with  coal  for  fuel, 
set  thirty-four  long  and  thirty-eight  high.  They  burn  from  ten 
to  twelve  days,  and  use  considerable  clay  on  kilns,  as  the  heat 
shows  on  top.  They  fire  from  both  heads  at  all  times,  with 
partitions  in  centre  of  each  arch,  and  have  no  trouble  to  keep 
a  uniform  heat.  The  firm  are  satisfied  that  there  are  more  eco- 
nomical ways  of  burning,  and  will  introduce  them  in  their  plant. 

The  Evansville  Pressed  Brick  Co.,  of  Evansville,  Ind.,  use  a 
mixture  of  clays  for  producing  vitrified  street  paving  brick. 
Fire-clay,  obtained  from  Lincoln,  is  mixed  with  clay  obtained 
from  their  own  yards.  The  clay  is  first  thrown  into  a  dry  pan, 
where  it  is  crushed  by  two  large  rollers,  weighing  three  tons 
each.  It  is  ground  down  into  a  powder.  It  is  then  carried  by 
means  of  a  belt,  with  buckets  attached,  to  the  pug-mill,  where 
it  is  moistened  and  thoroughly  ground  and  mixed.  From  the 
pug-mill  it  passes  into  the  top  of  the  stiff-clay  machine.  Here 
the  process  of  mixing  is  concluded  and  the  clay  is  ready  for 
the  moulds.  By  suitable  mechanism  it  is  moulded  under  a 
pressure  of  50,000  pounds  to  the  brick.  This  makes  it  an  im- 
possibility for  defects  to  occur  within  the  finished  product. 
The  moulded  brick  then  passes  out  on  a  belt ;  it  is  cut  and 
placed  on  a  car.  When  500  are  obtained  the  car  is  pushed 
down  a  track  to  the  dry-house.  In  this  the  car  remains  for  a 
period  of  about  thirty-six  hours.  Steam  is  used  in  the  dry- 


MANUFACTURE   OF    STREET-PAVING   BRICK.  233 

house  and  temperature  gradually  increases.  After  leaving  the 
dry-house,  the  product  stands  until  it  is  ready  to  be  placed  in 
the  kilns  for  burning. 

The  burning  is  done  in  down-draft  kilns,  the  fires  being  held 
at  finishing  about  twenty-four  hours  longer  than  for  building 
brick. 

The  Purington  Paving  Brick  Co.,  of  Galesburg,  111.,  use  a 
shale  clay,  which  during  the  last  few  years  has  become  famous 
as  the  material  from  which  the  celebrated  Galesburg  paving 
brick  are  made.  The  shale  is  reduced  to  powder  by  being 
subjected  to  the  action  of  two  large  size  dry-pans,  and  after 
being  rendered  plastic  by  mixing  with  water,  is  formed  into 
brick  shape  by  two  stiff-clay  brick  machines.  From  the  ma- 
chines the  brick  pass  on  cars  into  a  steam  dryer.  Sixteen 
Eudaly  down-draft  kilns  are  used  in  which  to  thoroughly  burn 
and  vitrify  the  brick.  These  kilns  are  eighty-three  by  eighteen 
feet  inside  measurement.  Crude  oil  is  used  for  fuel  in  these 
works,  and  it  has  been  demonstrated  to  be  far  superior  to  wood 
or  coal,  and  the  quality  of  product  seems  to  be  better  and  the 
vitrification  more  thorough  and  complete. 

From  one-fourth  to  one-third  more  time  is  consumed  in 
burning  than  with  the  ordinary  building  brick.  In  burning, 
the  brick  shrinks  from  nine  inches  in  length  to  eight  inches, 
and  proportionately  in  other  directions.  It  is  thoroughly  vit- 
rified throughout,  and  weighs  five  pounds.  This  brick  will 
resist  the  best  steel  drill,  and  a  chip  will  scratch  glass. 

A  peculiarity  about  this  plant  is  that  no  tight  and  loose  pul- 
leys are  employed,  clutches  being  used  altogether. 

The  buildings  are  all  of  brick,  being  heated  by  steam,  and  it 
is  intended  to  run  winter  and  summer  continuously.  A  coil  of 
pipe  is  extended  under  the  dry-pans,  so  as  to  prevent  clay 
from  freezing. 

The  Ottumwa  Paving  Brick  and  Construction  Co.,  of 
Ottumwa,  Iowa,  use  a  mixture  of  strong  clay  and  shale.  The 
cars  when  loaded  are  drawn  up  into  the  clay  house  and  dumped. 
Here  workmen  shovel- the  clay  and  shale  into  a  dry-pan.  After 


234  BRICK,  TILES   AND   TERRA-COTTA. 

being  pulverized  as  fine  as  powder  the  material  is  hoisted  by 
means  of  an  elevator  to  the  pug-mill  on  the  second  floor,  where 
water  is  added  and  the  material  tempered.  The  material  next 
passes  by  gravity  to  the  brick  machine,  immediately  below, 
where  the  brick  is  rapidly  shaped  by  a  stiff-clay  brick  machine. 
As  fast  as  the  brick  are  made  they  are  loaded  on  cars  and  run 
into  the  artificial  dryer,  where  they  remain  twenty-four  hours. 
They  are  then  taken  from  the  dryer  and  placed  in  the  kiln  to 
be  burned,  this  occupying  some  ten  days. 

The  capacity  of  the  plant  is  50,000  brick  per  day  and  more 
than  that  number  is  frequently  made.  The  six  down-draft 
kilns  have  each  a  capacity  of  250,000  brick. 

The  buildings  at  present  occupied  by  the  plant  are  a  clay 
house,  30x100,  a  machine  room,  30x70,  and  an  artificial  dryer, 
30x140  feet. 


CHAPTER  VII. 

THE    MANUFACTURE   OF   DRY-CLAY  BRICK. 

THE  term  dry-clay  as  applied  to  the  manufacture  of  brick  is 
to  a  certain  extent  a  misnomer ;  it  would  be  more  truthful  to 
say  semi-dry-clay  brick,  for  the  clay  for  the  manufacture  of 
brick  by  the  dry-clay  system  is  gathered  with  a  view  to  obtain- 
ing it  as  dry  as  possible,  usually  by  plowing  shallow,  allowing 
the  clay  to  dry  in  the  sun,  and  then  gathering  it  and  storing  it 
in  sheds.  There  is,  however,  even  after  the  greatest  expendi- 
ture of  care,  a  sufficient  quantity  of  dampness  developed  after 
passing  the  clay  through  the  crushers  and  the  pulverizers  to 
enable  one  to  press  it  into  a  ball  by  the  pressure  of  the  hand, 
which  jcould  not  be  done  if  the  clay  was  perfectly  dry,  in  which 
condition  no  amount  of  pressure  developed  by  modern  machin- 
ery would  press  it  into  a  perfect  and  solid  brick  if  the  clay  were 
entirely  dry  and  free  from  water.  Brick  of  this  character  are 
not  a  mud  or  tempered-clay  brick ;  therefore,  for  the  purpose 
of  the  present  description,  we  will  call  it  a  dry-clay  brick,  as  it 
is  usually  spoken  of  and  termed  in  the  trade.  In  times  past 
there  was,  and  even  now  there  is,  a  great  deal  of  opposition  in 
certain  quarters  directed  against  the  manufacture  of  brick  by 
the  dry-clay  system,  but  this  opposition,  it  must  be  conceded, 
has  not  the  same  basis  that  existed  some  fifteen  or  twenty  years 
ago  against  this  new  system  of  brickmaking,  which  was  then 
seeking  to  introduce  itself  into  the  trade.  The  introduction  of 
the  system  of  dry- clay  brickmaking  into  the  city  of  St.  Louis, 
where  it  is  probably  now  better  developed  than  at  any  other 
point  in  the  United  States,  was  attended  with  many  disad- 
vantages and  drawbacks  owing  to  the  prejudice  at  that  time 
prevailing.  It  was  then  quite  a  common  thing  to  see  written 

(235) 


236  BRICK,  TILES   AND   TERRA-COTTA. 

in  specifications  that  "  no  dry-clay  brick  will  be  permitted  to  be 
used  in  the  work  described."  It  is  hard  now,  however,  to  pick 
up  a  specification  prepared  by  the  architects  in  and  near  St. 
Louis  that  does  not  explicitly  specify  that  "  dry-clay  brick 
shall  be  used,"  or  else  that  "  the  brick  employed  are  to  be  equal 
in  quality  to  dry-clay  brick." 

In  the  manufacture  of  brick  by  the  dry-clay  system,  vastly 
more  depends  upon  the  manipulation  and  treatment  of  the  clay 
and  the  burning  of  the  brick  than  is  the  case  with  reference  to 
brick  made  from  tempered  clay.  It  is  quite  true  that  there 
are  some  clays  which  are  naturally  unsuitable,  and  which  no 
amount  of  manipulation  or  experience  in  treating  can  be  made 
suitable  for  making  dry-clay  brick.  It  is,  however,  the  opinion  of 
the  writer  that  where  one  manufacturer  fails  on  this  account  a 
dozen  manufacturers  fail  for  a  lack  of  the  proper  knowledge  of 
how  to  manipulate  and  treat  the  clay  in  its  various  stages,  and  in 
the  burning.  It  is  an  axiom  that  different  clays  require  different 
treatment,  hence  it  does  not  matter  how  much  experience  a  per- 
son may  have  had  with  the  manufacture  of  dry-clay  brick  in  a 
given  place,  for  if  the  same  person  embarks  in  this  industry  in  a 
new  location  there  would  be  much  both  to  learn  and  to  unlearn, 
and  a  perfect  knowledge  of  the  new  clay  would  be  obtainable 
only  after  experience,  close  observation,  and  whole  or  partial 
failure  in  treating  the  clay. 

In  the  manufacture  of  brick  by  the  dry-clay  system  much 
more  depends  upon  the  burning  of  the  brick  than  is  the  case 
with  brick  made  from  tempered  clay.  In  other  words,  the 
writer  desires  to  say  that  as  between  insufficiently  burned  brick 
of  the  two  kinds,  those  made  from  tempered  clay  are  much  the 
best  for  durability  and  strength,  for  with  the  dry-clay  brick  the 
fire  must  supply  that  quality  imparted  by  water  and  mixing  in 
the  tempered-clay  brick,  namely,  a  thorough  kneading  together 
of  the  entire  body  of  clay  of  which  the  brick  is  composed. 
Brick  made  from  dry  clay,  notwithstanding  the  fact  that  they 
may  be  subjected  to  enormous  pressure  in  their  formation,  are 
at  best  no  more  than  bodies  of  fine  granulated  matter,  which 


MANUFACTURE   OF   DRY-CLAY   BRICK.  237 

cannot  have  perfect  cohesion  until  after  it  has  been  submitted 
to  a  heat  sufficient  in  its  intensity  to  fuse  the  fine  granulated 
atoms  together  into  one  solid  annealed  and  homogeneous  mass, 
in  which  case  the  body  of  granulated  clay  is  converted  into  a 
good  and  perfect  brick.  The  writer  has  now  before  him  sam- 
ples of  six  brick  of  the  different  kinds,  all  made  from  dry  clay ; 
four  of  these  brick  are  well  burned,  one  is  partially  burned,  and 
one  is  not  burned  at  all.  On  breaking  the  partially  burned  or 
salmon  brick  there  are  disclosed  the  infinitesimal  atoms  or  gran- 

O 

ules  of  which  the  brick  is  composed.  The  appearance  of  this 
brick  after  being  broken  is  similar  to  that  shown  on  breaking  the 
unburned  or  green  brick,  and  in  fact  the  partially  burned  brick 
presents  a  more  porous  condition  than  the  unburned  brick,  be- 
cause in  the  case  of  the  partially  burned  brick,  the  heat  to  which 
it  was  subjected  was  sufficient  to  destroy  a  large  portion  of  the 
vegetable  matter  contained  in  the  clay  of  which  the  brick  was 
made.  But  the  heat  to  which  this  partially  burnt  brick  was  sub- 
jected was  not  sufficient  in  degree  to  melt  or  fuse  the  granulated 
atoms  together  in  one  solid  mass,  such  as  is  found  to  be  the  case 
with  hard-burned  brick,  which  improve  in  quality  as  they  ap- 
proach complete  vitrification.  In  burning  dry-clay  brick  it  is 
not  unusual  to  find  some  of  them  in  the  kiln  that  have  been 
completely  vitrified,  and  when  broken  very  much  resemble  the 
appearance  of  flint  or  glass.  Brick  of  this  character,  however, 
are  the  exception,  as  it  is  not  the  purpose  or  desire  of  the  man- 
ufacturer to  burn  the  brick  to  such  a  degree  of  hardness,  and 
the  brick  so  burned  commonly  occupy  a  position  in  the  kiln  in 
which  they  come  in  direct  contact  with  the  flames. 

Salmon  brick,  molded  by  the  dry-clay  process,  are  largely 
employed  for  dwelling  houses  and  other  light  work,  and  are 
not  objectionable  when  they  are  kept  free  from  damp  positions, 
and  when  so  employed  answer  very  well  for  the  purposes  for 
which  they  are  used ;  but  in  warehouse  construction  and  simi- 
lar heavy^work  brick  of  this  character  are  practically  worthless. 

In  selecting  a  clay  suitable  for  the  manufacture  of  brick  by 
the  dry-clay  process,  it  will  become  apparent  from  what  has 


238  BRICK,  TILES   AND   TERRA-COTTA. 

already  been  said  in  the  foregoing  part  of  this  chapter  that  a  clay 
that  is  weak  in  its  texture  and  that  contains  a  fair  proportion 
of  silica  or  of  iron,  lime  or  other  fluxing  elements,  will  make  a 
better  class  of  dry-clay  brick  than  a  clay  of  a  stronger  nature, 
which  is  hard  to  flux  and  which  will  come  out  of  the  kiln  very 
much  in  the  same  condition  that  it  went  in. 

The  preparation  of  the  clay  is  a  very  important  part  of  the 
process  of  making  brick  by  the  dry-clay  method,  and  in  this 
connection  there  is  always  an  opportunity  to  acquire  knowledge 
by  closely  noting  the  peculiarities  of  the  clays  used. 

After  the  clay  has  been  dug  the  first  step  is  to  properly  dry 
the  clay,  and  usually  a  few  hours'  exposure  to  the  sun  and  wind 
is  sufficient  for  this  purpose. 

Richardson  says,  in  his  address  delivered  at  the  Second  An- 
nual Meeting  of  the  National  Brick  Manufacturers'  Association  : 
"  If  the  clay  is  near  the  surface,  it  is  generally  plowed  to  the 
depth  of  a  few  inches  and  left  on  the  beds  to  dry.  In  the  hot 
summer  months  the  clay  is  usually  allowed  to  remain  exposed 
only  about  two  hours,  but  in  the  spring  and  fall  it  is  well  to 
dry  a  day  and  have  but  one  plowing.  If  too  far  below  the  sur- 
face, or  on  ground  too  uneven  to  admit  of  plowing,  the  clay, 
after  having  been  mined  with  pick  and  shovel  in  the  usual 
manner,  is  conveyed  in  carts  to  large  drying  grounds,  over 
which  it  is  dumped  to  the  depth  of  about  a  foot.  I  know  of  no 
cheaper  way  of  getting  the  clay  upon  the  drying  grounds  than 
by  carts — tramways  cannot  be  used  advantageously,  as  the  clay 
must  be  dumped  over  so  large  a  space.  While  the  clay  is  upon 
the  drying  ground,  it  is  gone  over  several  times  with  a  disk 
harrow,  having  about  sixteen  knives  and  working  on  a  beam, 
and  so  arranged  that  it  can  be  turned  on  a  handle,  and  at  the 
same  time  that  the  knives  turn  they  cut  and  tear  and  break  up 
the  lumps  and  expose  fresh  portions  to  the  sun  and  air.  Some 
of  the  manufacturers  of  dry-clay  brick,  located  near  St.  Louis, 
Mo.,  use  an  apparatus  which  travels  back  and  forth  over  the 
plowed  clay  and  which  throws  it  up  into  ridges,  and  then  men 
throw  it  into  carts  with  shovels  and  it  is  then  hauled  to  the 


MANUFACTURE    OF   DRY-CLAY   BRICK.  239 

sheds.  When  the  clay,  or  a  portion  of  it,  has  become  suf- 
ficiently dry,  it  is  taken  by  wheel-scrapers  into  large  sheds  to 
be  stored  for  future  use.  The  proper  dryness  of  the  clay  de- 
pends upon  the  time  it  is  to  remain  in  the  sheds,  and  the  depth 
or  height  to  which  it  is  to  be  piled.  The  object  in  storing 
large  quantities  of  clay  is  not  only  to  insure  no  stoppage  during 
wet  weather,  but  to  allow  the  clay  to  sweat  and  become  uni- 
form in  moisture  throughout,  as  thereby  alone  can  good  results 
be  obtained,  and  the  longer  the  clay  remains  in  the  shed  the 
better  brick  it  will  make.  The  average  cost  of  getting  the  clay 
into  the  sheds  in  proper  condition  ranges  from  fifty-five  cents  to 
seventy  cents  per  thousand  when  the  clay  sheds  are  not  more 
than  500  feet  from  the  banks.  The  drying  grounds  are  between 
the  clay  beds  and  the  sheds.  The  entrance  to  the  shed,  if  only 
one,  is  in  the  centre  of  the  side  toward  the  drying  grounds,  so 
that  while  one  end  is  being  emptied  for  manufacture  the  other 
can  be  filled.  From  the  shed  the  clay  is  taken  to  the  elevator 
opposite  the  entrance,  either  by  scraper  or  tram  cars,  and  raised 
to  a  height  sufficient  to  allow  of  its  shooting  into  the  pulverizer 
screens  and  presses  without  being  again  elevated.  The  manner 
of  pulverizing  varies  much  with  different  clays,  generally  two 
pulverizers  being  necessary  and  two  cylindrical  revolving  sieves. 
No  single  pulverizer  will  prepare  for  the  press  all  the  clay  it  re- 
ceives, though  sometimes  one  is  made  to  do  the  work  by  putting 
through  it  a  second  time  that  which  has  not  been  pulverized 
fine  enough.  A  sieve  is  placed  over  the  press  to  prevent  any- 
thing but  fine  clay  from  being  admitted.  Such,  briefly,  is  the 
method  of  preparing  the  clay  for  dry-press  brick-making,  simple 
enough  in  description,  but  in  practice  more  complex,  and  in- 
volving more  difficulties  than  one  who  has  not  tried  it  can  have 
any  adequate  idea.  The  great  problem  is  to  get  the  clay  fine 
enough  and  at  the  same  time  of  the  proper  degree  of  moisture. 
The  clay  should  go  into  the  moulds  uniform  in  fineness  and 
dryness,  moist  enough  to  be  pressed  hard,  and  dry  enough  to 
allow  of  the  brick  being  set  immediately  in  the  kiln  thirty  to 
forty  high.  We  usually  say  that  the  clay  is  of  the  proper  dry- 


240  BRICK,  TILES    AND   TERRA-COTTA. 

ness  when  if  squeezed  in  the  hand  it  will  just  hold  together  and 
retain  form  after  the  pressure  has  been  removed.  To  get  it 
into  this  condition  is  not  an  easy  matter.  If  the  clay  is  too 
moist  it  cannot  be  pulverized  fine  enough ;  if  too  hard  it  cannot 
be  pressed  hard  enough.  Brick  presses  will  generally  work 
damper  clay  than  pulverizers.  Strong,  plastic  clays  work  best, 
as  they  can  be  pressed  in  a  drier  state  than  weak,  sandy  clays. 
In  considering  this  question,  however,  regard  must  always  be 
had  to  difference  in  clays  and  machinery.  It  is  of  the  greatest 
importance  that  machinery  be  selected  suitable  to  the  clay. 
No  machine  has  ever  been  constructed  that  will  work  success- 
fully all  clays,  and  some  machines  are  failures  under  ordinary 
circumstances,  and  have  ruined  many  a  man's  business. 

"  To  one  about  to  undertake  the  making  of  brick  by  the  dry 
process,  no  better  advice  can  be  given  than  the  following: 
First,  secure  the  services  of  a  competent  brick  engineer,  with 
long  experience  in  the  process,  to  lay  out  the  yard,  select  and 
arrange  the  machinery,  and  put  everything  in  good  running 
order.  Do  not  mind  the  salary  you  may  have  to  pay  him ;  if 
he  is  the  right  man  he  will  save  you  ten  times  the  amount,  and 
perhaps  prevent  financial  ruin. 

"  It  is  important  to  store  a  large  quantity  of  clay  in  sheds, 
enough  for  two  or  three  months'  run,  or  longer.  With  some 
clays  this  is  absolutely  necessary  in  order  to  get  good  results. 
Now,  the  finer  the  clay,  the  freer  from  stones  and  lumps,  the 
sooner  will  it  become  fit  for  use.  The  plan  of  setting  a  coarse 
pulverizer  and  stone  separator  just  at  the  entrance  to  the  shed  is 
a  good  one.  This  would  make  the  further  separation  of  the  clay 
much  easier,  and  would  not  increase  the  cost  to  any  appreciable 
extent.  One  difficult  operation,  however,  still  remains,  before 
the  clay  is  fit  for  the  press.  Supposing  the  clay  to  be  well- 
tempered,  of  the  proper  degree  of  moisture  and  uniform 
throughout  the  pile,  yet  it  is  not  fine  enough  to  be  made  into  a 
good  brick,  and  must  be  put  through  another  pulverizer.  The 
clay  may  be  dry  enough  to  press  well,  and  yet  so  damp  as  to 
clog  the  pulverizer  and  cause  so  much  waste  in  tailings  that  the 


MANUFACTURE   OF    DRY-CLAY   BRICK.  241 

presses  must  be  stopped  occasionally  for  lack  of  clay ;  not  only 
this,  but  the  pulverizer  will  sooner  wear  out  and  need  repairing, 
perhaps  necessitating  more  stops.  In  order  to  make  the  busi- 
ness prosperous,  the  process  must  be  kept  running,  for  every 
minute  that  a  press  making  15,000  bricks  a  day  is  stopped,  a 
loss  is  entailed  of  25  to  50  cents.  Five  to  ten  dollars  a  day 
may  easily  be  lost  in  this  way,  and  perhaps  at  the  end  of  the 
season  leave  a  balance  on  the  wrong  side  of  the  ledger. 

"  Some  manufacturers  may  have  no  trouble  in  this  or  may 
have  success  in  obviating  it.  An  ingenious  man  will  often  pro- 
vide a  remedy.  The  clay  can  be  easily  pulverized  dry,  too  dry 
for  the  press,  and  afterwards  dampened  by  placing  a  steam 
pipe,  perforated  with  small  holes  and  wrapped  with  cloth,  just 
at  the  end  of  the  shoot  leading  from  the  pulverizer." 

DRY-CLAY   PULVERIZERS. 

The  machinery  for  pulverizing  is  a  matter  largely  determined 
by  the  nature  of  the  clay  to  be  handled.  As  a  general  thing, 
if  the  clay  is  reasonably  free  from  stone,  a  dry  pan  crusher  is 
the  best,  although  by  no  means  the  -cheapest.  The  pan  having 
a  perforated  bottom,  the  clay  running  through  the  perforations 
falls  into  an  elevator  boot,  and  is  then  conducted  as  high  as  the 
building  will  permit.  When  up  to  its  furthest  height,  it  is  run 
over  inclined  screens  lying  at  an  angle  of  about  45°,  the  clay 
fine  enough  for  the  press  runs  through  the  meshes  of  the  sieve, 
while  the  tailings  are  conveyed  back  to  the  dry  pan  to  be  re- 
ground.  There  are  other  ways  to  prepare  clay,  requiring  a 
somewhat  less  expensive  plant,  and  which  do  very  well,  pro- 
vided the  clay  is  not  too  strong.  Smooth  rolls  geared  together, 
having  a  differential  motion,  are  the  prototype  of  this  class  of 
machinery,  usually  called  disintegrators.  These  have  been 
greatly  improved  by  the  many  excellent  machines  made  by 
different  makers.  The  object  to  be  attained,  and  which  has 
made  a  departure  from  the  old-fashioned  smooth  rolls  a  neces- 
sity, is  to  prevent  the  clay  from  being  laminated  or  rendered 
flaky.  Clay,  instead  of  being  crushed  or  flattened,  should  be 
16 


242  BRICK,  TILES   AND   TERRA-COTTA. 

treated  exactly  in  the  opposite  way,  viz. :  It  should  be  torn  to 
pieces,  and  to  attain  this  object  to  perfection  is  the  goal  to  be 
arrived  at  by  the  manufacturers  of  pulverizing  machinery.  In 
using  a  dry  pan  this  difficulty  is  to  some  extent,  although  not 
altogether,  obviated  by  the  continued  stirring  up  of  the  clay 
before  the  rollers.  It  is  sometimes  the  practice  to  run  clay 
through  the  reels  after  going  through  the  disintegrator,  instead 
of  over  the  inclined  screens,  as  before  mentioned. 

When  stones  are  mixed  with  the  clay  in  the  bed,  the  ordinary 
method  of  manipulation  must  be  abandoned.  It  is  not  long  since 
that  a  bed  of  clay  having  many  stones  interspersed  through- 
out its  mass  was  considered  practically  useless  for  dry-press 
front  brick,  no  matter  how  excellent  the  clay  may  have  been  in 
itself.  As  a  general  thing,  when  this  is  the  case,  it  is  only  nec- 
essary to  adopt  a  method  of  manipulation  by  which  the  stones 
are  taken  out  of  the  clay  and  thrown  to  one  side.  Unless  there 
are  a  very  few,  it  is  poor  practice  to  crush  them  up  with  the 
clay.  Inventors  in  the  line  of  clay  pulverizing  machinery  have 
striven  hard  to  produce  a  machine  that  will  accomplish  easily 
and  surely  this  much-to-be-desired  object. 

From  the  pulverizers  the  clay  is  next  carried  by  means  of  an 
elevator  belt  or  otherwise  to  the  hopper  of  the  brick  machine. 

There  have  been  of  late  so  many  improvements  made  in 
machines  for  moulding  clay  by  the  dry-clay  process  that  there 
are  now  in  the  market  a  large  number  of  such  brick  presses 
which  are  claimed  to  be  fully  adapted  to  the  purpose  for  which 
they  are  designed.  In  selecting  a  machine  of  this  character 
care  should  be  had  that  it  be  as  simple  as  possible  in  its  mechan- 
ism, that  the  material  used  in  its  construction  is  of  the  best 
quality.  Owing  to  the  enormous  strain  to  which  machines  of 
this  class  are  exposed,  a  large  amount  of  money  is  annually 
lost  because  of  the  poor  quality  of  the  iron  or  steel  used  in 
castings  or  other  parts,  thereby  causing  breakages  to  occur 
which  would  not  otherwise  take  place.  It  of  course  becomes 
apparent  that  in  matters  of  this  character  the  purchaser  has  to 
rely  largely  upon  the  reputation  of  the  makers  of  the  machines, 


MANUFACTURE   OF   DRY-CLAY   BRICK.  243 

and  the  subject  should  receive  attention  at  the  time  when  the 
contract  of  purchase  is  made. 

DRY-CLAY  BRICK  MACHINES. 

There  has  been  unquestionably  a  great  advance  in  recent 
years  in  dry-press  machines.  Those  that  pressed  the  clay  from 
one  side  only  are  now  universally  condemned,  as  it  left  the  side 
of  the  brick  furthest  away  from  the  pressure  soft  and  without 
strength.  There  is  no  doubt,  however,  but  they  were  the  fore- 
runners of  our  present  presses.  It  was  soon  discovered  that  to 
make  both  sides  of  the  brick  equally  hard  and  strong,  it  was 
necessary  to  make  the  machine  so  that  both  sides  of  the  brick 
should  receive  equal  pressure.  This  idea  insured  both  edges 
strong  and  sharp.  But  what  about  the  centre?  Ah,  "there's 
the  trouble."  An  ugly  granulated  central  seam  running  around 
the  middle  of  the  face  of  the  brick  was  for  years  the  unmistak- 
able mark  of  a  dry-pressed  brick,  and  that  is  where  those  man- 
ufacturing by  the  re-press  process  made  their  strongest  argu- 
ment. They  could  point  with  the  ringer  of  pride  to  their  brick 
having  no  such  ugly  defacement,  and  it  cannot  be  denied  that 
their  argument  was  a  just  one.  The  dry  process  could  never 
hope  to  compete  successfully  with  the  re-pressed  method  until 
this  fatal  objection  was  overcome.  It  is  safe  to  predict  that 
machines  having  this  drawback  are  doomed,  and  that  they  will 
in  the  immediate  future  be  abandoned.  In  some  machines  it  is 
claimed  that  this  objection  has  been  entirely  overcome. 

Another  important  question  regarding  a  dry  press  is  its 
strength.  To  make  a  good  ringing  brick  the  particles  of  clay 
must  be  pressed  together  into  as  dense  a  condition  as  possible. 
Should  it  not  receive  the  requisite  pressure,  the  brick  will  be 
shaky  and  fail  to  have  a  genuine  ring,  even  when  the  clay  is  of 
an  easily  vitrifiable  character.  To  withstand  this  pressure  great 
strength  is  required  in  the  machine. 

The  greatest  difficulty  that  machine  men  have  to  contend 
with  is  the  lamentable  lack  of  knowledge  amongst  those  having 
charge  of  the  machine  after  it  leaves  the  shop  and  goes  into 


244  BRICK,  TILES   AND   TERRA-COTTA. 

actual  service.  It  is  an  easy  matter  for  a  careless  attendant  to 
ruin  a  machine  and  spoil  the  reputation  of  its  builder.  A  fre- 
quent mistake  made  by  those  using  dry-press  machinery  is  the 
straining  of  the  machine  to  its  utmost  capacity.  In  pressed 
brick  it  is  the  quality  of  the  product  that  tells  and  not  the 
quantity,  and  very  often  the  former  is  sacrificed  to  the  latter. 
Of  course,  when  the  dry  process  is  adopted  to  make  common 
brick,  then  in  that  case  it  is  necessary  to  work  up  to  the  limit 
with  little  regard  to  the  beauty  of  the  product. 

DRYING. 

If  the  brick  are  to  be  dried  in  the  open  air,  the  nature  of  the 
clay  should  be  studied  so  that  the  current  of  air  admitted  to  the 
drying  apartment  will  not  be  sufficient  to  crack,  warp,  or  in 
other  way  injure  the  green  brick.  If  the  brick  are  to  be  dried  by 
artificial  means  the  method  employed  will  depend  largely  upon 
local  circumstances.  If  an  abundance  of  fuel  can  be  obtained 
near  by,  and  at  low  cost,  it  may  in  some  instances  be  cheaper 
to  place  the  moulded  brick  upon  cars  suitably  built  of  iron, 
and  have  them  conveyed  to  a  drying  tunnel,  at  one  end  of 
which  there  is  a  furnace,  and  at  the  opposite  end  a  chimney  or 
stack,  in  which  case  the  brick  will  be  dried  by  coming  in  actual 
cantact  with  the  flame  and  heat  of  the  furnace.  In  some  cases 
these  drying  furnaces  are  so  constructed  as  to  utilize  the  heat 
derived  from  kilns  of  brick  in  process  of  burning,  and  from 
which  the  water-smoke  or  steam  has  been  previously  driven  off. 
In  all  such  methods  of  rapid  drying,  care  should  be  observed 
that  the  surfaces  of  the  brick  are  not  dried  so  rapidly  as  to 
cause  the  shrinkage  of  these  surfaces,  and  hence  the  cracking, 
which  greatly  disfigures  the  appearance  of  the  brick  and  lowers 
their  commercial  value. 

A  large  number  of  works  manufacturing  brick  by  the  dry- 
clay  process  use  steam  for  drying  purposes,  the  steam-pipes 
being  so  located  in  the  drying  chamber  as  to  give  a  uniform 
temperature  throughout,  exhaust  steam  being  utilized  for  dry- 
ing the  brick  during  the  day,  and  live  steam  being  employed 


MANUFACTURE   OF   DRY-CLAY   BRICK.  245 

at  night.  Where  steam  is  used  for  drying  the  brick  it  is  essen- 
tial that  the  drying  apartment  should  be  provided  with  ade- 
quate means  of  ventilation,  in  order  that  the  moisture  generated 
from  the  brick  may  be  carried  off  as  rapidly  as  possible. 

BURNING. 

The  manner  of  setting  dry-clay  brick  does  not  differ  materi- 
ally from  the  method  of  setting  tempered-clay  brick.  The  kiln 
having  been  thoroughly  daubed  on  its  interior  faces  and  all 
holes  and  cracks  faithfully  stopped,  a  careful  examination  of 
the  floor  of  the  kiln  should  be  made,  and  if  coal  is  the  fuel  to 
be  employed  for  burning  the  brick,  all  grate  bars  should  be 
inspected  and  defective  ones  removed  or  repaired.  In  burning 
dry-clay  brick  it  is  absolutely  necessary  that  the  floor  of  the 
kiln  be  kept  as  dry  as  possible,  for  if  there  be  damp  places  the 
bottom  courses  of  the  brick  are  liable  to  crush  and  cause  seri- 
ous inconvenience  in  firing  and  in  estimating  the  natural  settle- 
ment of  the  kiln  in  the  final  burning.  Where  there  are  places 
showing  moisture  it  is  better  to  use  salmon  brick  for  the  bottom 
course ;  the  difference  in  the  widtl\  between  the  salmon  brick 
and  the  green  brick  can  be  made  up  with  loam  placed  on  the 
bottom  of  the  kiln.  The  height  to  which  the  brick  are  to  be 
set  depends  largely  upon  the  nature  of  the  clay  and  of  course 
upon  the  style  and  condition  of  the  kilns.  The  writer  in  the 
manufacture  of  this  class  of  brick  employed  the  open  or  Dutch 
kiln,  and  usually  set  the  brick  about  42  high,  14  courses  in  the 
arches,  14  courses  on  the  lower  bench,  and  14  courses  on  the 
upper  bench,  and  used  two  courses  of  burned  brick  for  platting. 
The  object  in  using  the  two  courses  of  burned  brick,  or  rather 
salmon  brick,  for  platting  was  to  hold  the  heat  as  long  as  pos- 
sible, and  then  it  was  found  by  experience  that  where  the  green 
brick  were  used  for  platting  it  was  difficult  to  walk  over  them 
in  tightening  the  platting  courses  without  breaking  or  crushing, 
and  where  the  brick  were  crushed  defective  places  would  occur 
in  the  kiln  to  a  depth  of  four  or  five  courses  below  these  defect- 
ive or  crushed  brick,  and  the  loss  entailed  was  greater  than 
the  cost  of  using  the  salmon  brick  for  the  platting  courses. 


246  BRICK,  TILES   AND   TERRA-COTTA. 

The  brick  having  been  set  in  the  kiln  and  the  bestowing 
properly  put  up,  daubed  and  braced,  and  every  alternate  brick 
of  the  top  or  platting  course  set  upon  its  end,  the  kiln  of  brick 
is  ready  for  burning.  In  firing  dry-clay  brick,  no  matter  how 
thoroughly  or  carefully  they  may  have  been  dried,  it  is  abso- 
lutely essential  that  the  early  stages  of  burning  should  be  con- 
ducted cautiously  and  that  no  attempt  should  be  made  to  drive 
off  the  water-smoke  too  quickly,  only  a  very  light  fire  should 
be  made  in  the  mouths  of  the  arches,  and  only  on  that  side  of 
the  kiln  which  will  allow  the  smoke  to  be  driven  or  blown  en- 
tirely through  the  arches,  fire  being  made  only  on  the  wind- 
ward side.  The  fire  should  be  increased  very  slowly,  and  in 
some  instances  ought  not  to  be  crossed  inside  of  seventy-two 
hours.  The  great  object  in  the  early  stages  in  burning  dry- 
clay  brick  is  to  drive  off  the  water-smoke  from  the  brick  with- 
out increasing  the  volume  of  air  contained  in  the  brick  and 
disseminated  between  the  granules.  If  the  air  thus  contained 
in  the  brick  should  become  heated  too  rapidly,  it  will  expand 
and  it  will  be  almost  impossible  at  any  future  stage  of  the 
burning  to  bring  the  granules  of  clay  in  the  same  intimate  con- 
tact that  they  were  before  the  expansion  of  the  air,  and  then, 
again,  from  the  swelling  of  the  brick  injury  results  to  the  kiln. 
Time  spent  in  the  early  stages  of  burning  this  class  of  brick 
should  not  be  considered  wasted ;  no  effort  should  be  made  to 
push  the  burning  until  the  limit  of  water  shrinkage  has  been 
reached,  which  is  just  before  the  last  particle  of  water-smoke 
has  disappeared,  and  from  this  point  on  to  the  final  firing  the 
kiln  of  brick  should  be  pushed  more  quickly  and  under  heavier 
firing  than  is  usually  given  to  tempered-clay  brick.  Perhaps  it 
may  not  be  amiss  to  repeat  more  fully  at  this  point  a  former 
explanation  of  what  is  meant  by  "  the  limit  of  the  water  shrink 
age."  The  hydrous  silicate  of  alumina,  or  pure  clay,  being 
infusible  even  under  the  most  intense  heat,  possesses  no  power 
of  shrinkage  in  burning.  Brick  clays,  however,  are  not  pure 
clays ;  they  are  mixed  with  the  alkalies,  or  alkaline  earths,  and 
they  are  fusible  in  proportion  to  the  admixture.  Now  aluminum 


MANUFACTURE   OF   DRY-CLAY   BRICK.  247 

hydrate,  like  silicic  acid,  is  capable  of  assuming  the  gelatinous 
form,  in  which,  owing  to  the  peculiar  arrangement  of  the  atoms, 
these  compounds  are  able  to  take  up  a  large  quantity  of  water 
swelling  or  binding  together  sandy  or  earthy  matter  in  a  fine 
state  of  division.  On  removing  the  water  by  drying,  the  origi- 
nal mass  shrivels  up ;  this  is  termed  shrinkage.  Either  on 
drying  in  the  air  or  on  burning,  the  atoms  of  clay  approach 
one  another  more  closely,  the  accompanying  admixed  constit- 
uents also  at  the  same  time  being  drawn  together.  An  increase 
of  density  and  diminution  of  bulk  thus  occur.  It  has  been 
shown  that,  by  gradually  drying  brick  clays  at  a  temperature 
increasing  to  the  necessary  point,  the  shrinkage  did  not  con- 
tinue until  the  clay  was  quite  dry,  but  ceased  before  this  point 
was  reached. 

To  a  certain  stage  the  shrinkage  exactly  expressed  the  loss 
of  water ;  at  this  point  it  suddenly  stopped,  just  as  the  clay 
particles  came  into  contact.  This  point  is  termed  the  "  limit 
of  shrinkage,"  and  the  water  dissipated  to  this  point  is  distin- 
guished as  the  "water  of  shrinking,"  and  that  subsequently 
driven  off  as  the  "  water  of  porosity."  The  sum  of  the  two  is 
total  water,  and  is  the  "  limit  of  water  shrinkage." 

The  proportion  of  pores  in  the  dry  clay  is  constant,  that  is, 
independent  of  the  water  originally  contained.  From  the  fact 
that  the  proportion  of  pores  in  several  chemically  different  clays 
is  nearly  equal,  it  may  be  inferred  that  the  smaller  atoms  of 
clay  have  a  regular  spherical  shape,  and  this  view  is  confirmed 
by  microscopic  observations. 

In  brick  made  from  tempered  clay  there  are  thus  a  vast 
number  of  these  little  spheres  at  equal  distance,  and  surrounded 
by  a  greater  or  less  quantity  of  water.  In  dry-clay  brick  these 
little  spheres  are  brought  more  closely  together  than  in  tem- 
pered-clay  brick.  The  distance  between  these  particles  is  so 
small  that  the  attraction  between  them  is  considerable,  so  that 
a  system  of  capillary  tubes  is  formed,  in  which  expulsion  of 
water  by  pressure  is  so  opposed  that  neither  the  power  of  at- 
traction of  the  spherical  atoms  for  one  another,  nor  their  verti- 


248  BRICK,  TILES   AND   TERRA-COTTA. 

cal  downward  pressure,  will  permit  the  water  to  penetrate 
through  the  tubes.  In  shrinking,  as  water  evaporates  on  the 
surface,  a  fresh  supply  is  drawn  from  the  interior  of  the  mass, 
through  the  fine  capillary  tubes  mentioned  above,  the  particles 
approximating  throughout  the  whole  mass,  in  obedience  to 
their  power  of  attraction ;  and  this  process  continues  until  the 
atoms  come  in  actual  contact,  and  then  room  for  water  is 
afforded  only  in  the  spaces  between  the  particles  (water  of 
porosity).  In  meagre  clays  these  fine  spherical  atoms  envelop 
the  irregular-shaped  particles  of  foreign  matter.  On  trying  the 
effect  of  additions  of  very  fine  sand  to  some  washed  clay,  it  was 
found  that  to  a  certain  point  the  shrinking  power  of  the  clay 
increased  with  its  progressive  meagreness  (the  water  being 
constant),  and  the  porosity  decreased.  This  point  is  termed 
the  "  point  of  greatest  density  of  the  mass." 

From  the  point  of  greatest  density  further  impoverishment 
diminishes  the  shrinkage  for  an  equal  amount  of  water  in  the 
pores,  but  increases  the  porosity. 

Hence  it  is  that  brick  made  of  moderately  strong  clay  by  the 
dry-clay  process  are  not  in  condition  to  commence  to  receive 
hard  firing  until  just  before  the  last  of  the  water-smoke  leaves 
the  kiln. 

The  proportion  of  fuel  required  to  burn  a  kiln  of  dry-clay 
brick,  because  of  their  greater  density,  averages  from  one-sixth 
to  one-quarter  more  than  for  brick  made  from  tempered  clay. 
The  amount  of  settling  to  which  the  kiln  is  to  be  subjected  de- 
pends, of  course,  upon  the  nature  of  the  clay,  and  this  can  be 
determined  only  through  practical  experience.  After  the  kiln 
has  been  burned  it  should  remain  closed  for  four  or  five  days, 
and  even  longer,  if  the  time  can  be  spared,  as  kilns  of  brick 
made  from  dry  clay  are  injured  by  being  exposed  too  quickly 
to  the  cooling  process  after  burning. 

SEMI-PLASTIC   BRICK. 

There  are  recent  modifications  of  machinery  which  provide 
for  added  moisture  to  the  clay,  and  which  have  resulted  in  the 


MANUFACTURE   OF   ErRY-CLAY   BRICK. 


249 


production  of  brick  which  fairly  overcome  the  former  defects 
and  obviate  criticism,  making  the  brick  a  semi-plastic  rather 
than  a  dry-clay  brick. 

This  machine  is  shown  in  Fig.  67,  and  is  made  by  the  Frey- 
Sheckler  Co. 

FIG.  67. 


SEMI-PLASTIC   BRICK   PRESS. 


In  the  construction  of  this  machine  the  manufacturers  have 
endeavored  to  so  design  it  that  it  will  completely  fulfil  the 
most  exacting  conditions,  and  they  claim  for  it  the  following 
advantages : 

First :  It  exerts  a  greater  pressure  than  any  other  machine 
of  its  class,  and  this  pressure  is  retained  on  the  brick  until  they 
are  delivered  from  the  mould. 

Second :  Simplicity  of  construction,  easy  accessibility,  and 
immense  strength. 

Third :  It  leaves  no  granulations  on  the  outside  surface  of 
the  brick. 


250  BRICK,  TILES   AND   TERRA-COTTA. 

Fourth :   All  the  rectangular  edges  of  the  brick  are  perfect. 

This  machine  is  built  in  two  sizes,  viz. :  Two  and  four  mould. 
Capacity  of  two  mould,  10,000  to  12,000  brick  per  day,  and 
will  consume  about  four  horse-power.  Capacity  of  four  mould, 
20,000  to  25,000  brick  per  day,  and  will  consume  about  eight 
horse-power. 

These  machines  have  been  thoroughly  tested,  and  are  sold 
under  a  guarantee. 


CHAPTER  VIII. 

THE   MANUFACTURE    OF   PRESSED   AND    ORNAMENTAL   BRICK. 

PRESSED    BRICK. 

PRESSED  or  front  brick  are  produced  by  a  combination  of  the 
hand-made  and  the  machine  processes.  The  finishing  of  brick 
of  this  class  is  sometimes  done  in  a  press  run  by  steam-power. 
The  usual  way  is  to  mould  the  brick  by  hand  and  make  them 
slightly  larger  than  the  size  of  the  press-box  in  which  they  are 
to  be  finished. 

The  moulding,  drying,  and  pressing  of  front  brick  are  con- 
ducted entirely  under  shelter ;  the  hand-press  gang  is  composed 
of  three  members :  the  moulder,  who  also  does  the  pressing ; 
the  temperer,  who  also  does  the  wheeling  of  the  clay ;  and  the 
off-bearer,  who  also  rubs  the  finished  brick  with  very  fine 
moulding  sand. 

A  day's  work  for  the  press-gang  is  to  temper  the  clay, 
mould,  press,  and  finish  one  thousand  one  hundred  and  sixty- 
seven  brick.  Pressed  brick  are  seldom  hacked  on  edge  in  the 
sheds,  but  are  laid  flatwise,  each  pile  being  a  separate  one,  and 
a  space  of  about  three  inches  is  left  around  each  hack ;  they 
hold  shape  better  in  this  manner  of  drying  than  if  hacked  on 
edge,  and  after  they  have  been  pressed  they  are  hacked  differ- 
ently, as  will  be  explained. 

For  the  information  of  brick-makers  in  distant  places,  where 
pressed  brick  have  not  been  made,  we  elaborate  further  upon 
the  general  plan  of  making  them  by  hand. 

It  is  important  that  the  clay  should  be  well  tempered,  the 
clay-tempering-wheel  producing  the  best.  The  brick  should  be 
moulded  free  from  flaws  or  sand-cracks,  and  the  mould,  when 
in  use,  should  be  kept  well  cleaned.  Those  in  general  use  in 

(251) 


252  BRICK,  TILES   AND   TERRA-COTTA. 

Philadelphia  are  known  as  the  "  single  cast-iron  moulds."  The 
moulding  sand  is  an  important  item  in  making  pressed  brick, 
as  the  color  and  smoothness  of  the  brick  depend  on  it.  A 
sieve  having  about  sixty  meshes  to  the  lineal  inch  is  used  for 
preparing  the  sand  for  moulding  the  brick.  The  brick  are 
placed  flat  on  the  floor,  and  when  pretty  dry,  a  light  sieving  of 
sand  is  put  over  the  faces.  They  are  then  turned  over  that 
they  may  dry  more  regularly.  Sheds  built  expressly  for  the 
purpose  are  also  used  for  pressed  brick.  The  roof  is  made  to 
open  so  as  to  admit  wind  and  sun  when  required.  Where  the 
brick  dry  too  fast,  a  piece  of  damp  carpet  can  be  laid  over 
them  and  sprinkled  occasionally  with  water.  When  the  brick 
are  in  a  proper  state  for  pressing — say,  when  they  can  be 
handled  without  finger-marks — the  press  is  taken  to  the  brick 
by  placing  the  press  on  boards,  the  brick  are  carefully  put  into 
the  mould,  great  care  being  exercised  that  they  are  not  marked 
in  dropping  them  in.  There  must  be  no  finger-marks  on  them, 
and  all  "crumbs"  must  be  wiped  off  the  face  of  the  mould; 
also  off  the  lid.  After  the  brick  are  pressed  they  are  generally 
laid  flat,  five  or  six  high,  and  when  partly  dry  they  are  slightly 
rubbed  with  the  hand  and  piled  pigeon-hole  shape,  which  al- 
lows further  drying.  In  some  cases  they  are  piled  in  squares, 
edgewise,  five  or  six  high.  When  dry  enough,  they  are  placed 
on  barrows,  with  strips  of  wood  or  soft  blankets  between  each 
course,  and  taken  to  the  shed  to  remain  until  required  for 
burning.  It  is  highly  important  that  the  mould  lid  and  plate 
of  the  press  shall  be  kept  clean  when  in  use.  Occasionally 
raise  the  plunger  plate,  and  wipe  off  any  dirt  that  may  have  ac- 
cumulated on  it,  and  apply  a  slight  oiling  to  all  the  parts. 
When  the  day's  work  of  pressing  is  ended,  make  it  a  fixed  rule 
that  the  presser  shall  take  out  the  plunger,  clean  the  mould  lid 
and  plate,  oil  the  surfaces  and  replace.  Occasionally,  while 
working,  the  presser  should  clean  the  plunger  and  keep  it  al- 
ways well  oiled,  as  should  be  all  the  wearing  parts  of  the  press. 
The  pressed  brick  are  usually  set  eight  courses  high  in  the 
kilns,  but  we  have  seen  them  carried  ten  or  twelve  courses  in 


MANUFACTURE  OF  PRESSED  AND  ORNAMENTAL  BRICK.      253 


FIG.  68. 


^Common  Brick 


height  in  the  city  of  Philadelphia.  The  top  course  does  not 
usually  extend  closer  than  the  fourth  course  from  the  top. 
They  are  also  set  differently  from  the  way  in  which  common 
brick  are  placed,  the  desire  being  to  preserve  the  faces  which 
are  to  be  exposed  in  the  wall  of  a  building.  There  is  not  the 
same  amount  of  crossing  or  "checkering"  of  this  class  of  brick 
as  in  the  common  stock. 

The  bottom,  one  middle,  and  the  top  course,  are  crossed  or 
checkered  in  setting  eight  high,  and 
Fig.  68  will  show  the  manner  of  plac- 
ing them  in  the  kiln.  The  brick  are 
set  one  directly  over  the  other  on 
edge  ;  the  "  cross-ties"  shown  are  to 
hold  the  body  and  keep  the  pressed 
brick  from  "wabbling"  or  slanting 
from  either  side.  Great  care  and 
experience  in  setting  as  well  as  in 
burning  kilns  containing  quantities 
of  pressed  brick  are  very  essential. 
Too  hard  firing  in  settling  the  kilr^is 
liable  to  cause  all  the  pressed  brick 
to  "  tumble"  or  fall,  and  the  fires  at 
this  stage  are  consequently  lighter 
and  more  frequent  than  when  the 
kiln  contains  only  common  brick. 


Common  Brick 


The   pressed   brick  are  also   handled    ELEVATION  SHOWING  MANNER  OF 

,  r     11         ,1  SETTING      PRESSED      BRICK     IN 

much  more  carefully  than   common       THE  KILN. 

brick,  being  taken  up  one  at  a  time, 

placed  lightly  on  barrows,  and  are  carefully  handled  and  tossed 

also  one  at  a  time  to  the  setter.     No  extra  money  is  paid  to  the 

setting  gangs  for  handling  pressed  brick ;  the  work  is  included 

in  the  task. 

In  all  stages  the  "  gluts"  as  well  as  the  finished  green  pressed 
brick  should  be  protected  from  unequal  drying ;  the  sheds  in 
which  they  are  made  should  have  movable  slat  sides,  which  are 
closed  during  periods  of  strong  winds. 


254  BRICK,  TILES   AND   TERRA-COTTA. 

When  the  "  gluts"  for  pressed  brick  are  made  by  machinery, 
the  clay  should  be  wet,  and  the  brick,  when  they  issue  from  the 
machine,  should  be  soft  enough  to  allow  the  finger  to  be  forced 
into  them.  The  gangs  which  re-press  machine-made  front  brick 
are  composed  of  four  persons,  if  handled  on  barrows,  and  three 
if  handled  in  the  brick  cars,  the  members  of  the  gang  being 
the  presser,  off-bearer  and  rubber,  or  sander.  The  brick  are 
run  through  in  a  hurry,  three  thousand  being  a  day's  work. 
Brick  made  in  this  way  are  not  usually  suitable  for  the  lower 
story  fronts  of  fine  buildings ;  but,  when  economy  is  an  object, 
they  can  be  used  in  the  upper  portions  where  their  defects  can- 
not so  easily  be  discovered.  This  is  hardly  honest,  but  a  great 
many  neat  fronts  are  thus  put  up  in  neighborhoods  that  would 
not  justify  the  employment  of  first  quality  and  high-priced  brick. 

When  care  is  taken  with  every  stage  of  the  work,  and  the 
"  gluts"  are  made  very  soft,  and  well  and  thoroughly  sanded 
and  rubbed,  it  is  possible  to  produce  pressed  and  ornamented 
brick  which  are  not  only  good  in  appearance,  but  which  are 
strong  and  durable,  and  which  can  with  safety  be  used  in  place 
of  first-quality  brick  for  cornices  and  other  work  occupying  a 
high  position  in  buildings. 

Geo.  Carnell,  of  Philadelphia,  Pa.,  the  well-known  manufac- 
turer of  hand  and  power  brick  presses,  gives  the  following  con- 
cise directions  for  making  fine  front  brick : 

1 .  It  is  important  that  the  clay  should  be  well  tempered,  a 
clay-tempering  wheel  producing  the  best. 

2.  It  is  necessary  to  have  sheds  built  expressly  for  that  pur- 
pose, the  roof  being  made  so  it  can  be  opened  to  admit  sun  and 
wind  when  required ;  doors  are  also  made  to  protect  the  sides 
of  the  shed  in  case  too  high  winds  prevail.     In  sheds  built  this 
way,  the  brick  can  be  dried  with  better  regularity. 

3.  The  brick  should  be  moulded   free   from   flaws  or  sand 
cracks ;  the  moulds,  when  in  use,  must  be  kept  well  cleaned  by 
the  off-bearer,  as  the  accumulation  of  sand  or  dirt  on  the  sides 
of  the  moulds,  if  not  scraped  off,  will  make  a  variation  in  the 
sizes  of  the  brick  when  they  come  to  be  pressed. 


MANUFACTURE  OF  PRESSED  AND  ORNAMENTAL  BRICK.     255 

4.  The  brick  are  placed  on  the  floor  to  dry.     When  nearly 
dry  a  light  sieving  of  sand  is  put  over  their  faces,  and  they  are 
then  turned  over  that  they  may  dry  more  regularly.     When 
the  brick  dry  too  fast  a  damp  carpet  can  be  placed  over  them 
and  sprinkled  occasionally  with  water. 

5.  When  the  brick  are  ready  for  pressing,  say  when  they 
can  be  handled  without  finger  marks,  the  press  is  then  taken 
to  the  brick  (or  vice  versa)  ;  the  brick  are  then  carefully  placed 
in  the  press  mould,  care  being  taken  that  they  are  not  marked 
while  dropping  them  in.     The  brick  must  be  kept  free  from 
finger  marks. 

6.  The  mould,  plate  and  lid  should  be  kept  clean ;  a  sharp- 
pointed  hard  wood  stick  is  best  to  clean  the  corners  of  the 
mould  out  with.     This  should  be  done,  and  the  mould  wiped 
out  every  few  brick ;  occasionally  it  will  be  found  necessary  to 
raise  the  bottom  plate  and  scrape  the  dirt  from  around  the 
sides ;  after  cleaning  apply  a  little  oil. 

7.  From  the  press  the  brick  are  carried  with  paddles  and 
laid  on  their  flats,  about  six  high. 

8.  When  the  brick  are  partly  dried  they  are  rubbed  carefully 
with  the  hand  and  hacked  on  their  edges,  pigeon-hole  shaped, 
for  drying.     By  pigeon-hole  hacking  we  mean  placing  the  brick 
two  on  two,  and  reversing  them  every  course.     After  they  have 
become  hard  enough  to  handle  without  danger  of  injuring  them 
they  are  placed  on  barrows,  with  pieces  of  soft  carpet  or  blanket 
between  the  courses ;   they  are  then  hacked  in  sheds  and  are 
ready  for  the  kiln. 

9.  After  the  day's  pressing  is  finished  take  the  plate  and 
plunger  out  of  the  mould,  scrape  all  the  dirt  off,  wipe  clean, 
and  oil  the  mould,  plates  and  plunger.     By  keeping  the  press 
and  mould  clean  it  will  give  better  satisfaction. 

The  following  paper  was  read  by  Mr.  William  Roberts,  of 
Trenton,  N.  J.,  at  the  Fifth  Annual  Convention  of  the  Na- 
tional Brick  Manufacturers'  Association,  Thursday,  January  22, 
1891.  The  paper  is  entitled,  "  Press  Brick:  Their  Manufacture 
and  Use." 


€CF  THE  ^        >k 

EVERSITT) 
OP  ,^^ 

SAUFORNjA^^ 


256  BRICK,  TILES    AND   TERRA-COTTA. 

"  I  hardly  think  it  necessary  for  me  to  go  into  a  lengthy  de- 
scription of  pressed  brick  or  their  manufacture  or  use  in  the 
past,  as  that  will  not  concern  the  members  of  this  Association  so 
much  as  a  general  discussion  and  interchange  of  ideas  and 
views  upon  matters  appertaining  to  their  manufacture  in  the 
present  and  for  the  future.  Of  course,  we  shall  take  our  expe- 
rience of  the  past  as  a  foundation  for  our  present  ideas. 

"The  term  pressed  brick  was  originally  meant  to  apply  to  a 
brick  that  should  be  first  moulded  and  then  re-pressed,  as  that 
has  been  the  customary  way  of  producing  brick  heretofore  spe- 
cified or  looked  upon  as  pressed  brick.  But  of  late  years  there 
has  been  manufactured  throughout  a  large  section  of  the  coun- 
try a  large  number  of  brick  that  of  course  might  be  termed 
pressed  brick.  For  instance,  all  the  brick  that  are  made  with 
what  are  called  dry-clay  brick  machines  are  certainly  pressed 
brick,  as  they  are  pressed  into  shape  by  the  same  kind  of  a  pro- 
cess as  are  our  regular  pressed  brick.  The  only  difference  in 
their  manufacture  is  that  in  making  brick  with  dry- clay  ma- 
chines, the  brick  are  pressed  into  form  direct  from  the  raw 
material,  while  what  we  have  always  heretofore  termed  in  the 
east  as  a  pressed  brick  have  in  all  cases  been  moulded  into  the 
form  of  a  brick  before  going  through  the  process  of  re-pressing, 
and  this  is  the  kind  of  a  brick  that  we  shall  particularly  allude 
to  in  the  reading  of  this  paper. 

"  About  the  first  pressed  brick  that  we  know  of  as  having 
been  made  in  the  east  for  the  general  trade  in  any  large  num- 
bers were  in  the  cities  of  Philadelphia  and  Baltimore  ;  in  fact,  we 
do  not  think  that  previous  to  twenty-five  years  ago  there  was 
any  place  that  manufactured  pressed  brick  outside  of  those  two 
cities,  that  is,  for  shipping  to  the  general  trade.  Of  course, 
there  were  some  few  pressed  brick  made  in  a  small  way  in 
other  places  for  local  consumption.  About  a  quarter  of  a  cen- 
tury ago  the  brick  manufacturers  of  the  city  of  Trenton,  N.  J., 
commenced  to  manufacture  a  few  pressed  brick  for  the  New 
York  market,  and  they  have  been  steadily  increasing  their  out- 
put up  to  the  present  time.  In  the  year  of  1870  the  city  of 


MANUFACTURE  OF  PRESSED  AND  ORNAMENTAL  BRICK.      257 

Trenton  produced  about  1,500,000  of  regular  pressed  brick. 
But  at  the  present  time  we  produce  annually  about  20,000,000 
of  pressed  brick,  all  of  them  being  made  in  the  regular  way,  by 
first  being  moulded  by  hand  one  at  a  time,  and  then  re-pressed 
with  hand  presses. 

"  We  have  no  statistics  showing  how  many  pressed  brick  are 
made  in  other  cities,  but  from  the  best  information  that  we  have 
been  able  to  obtain,  we  judge  that  the  city  of  Trenton  is  about 
the  second  city  in  the  number  made  annually  of  this  particular 
class  of  brick,  the  city  of  Philadelphia  being  first  and  Baltimore 
third. 

As  far  as  brickmaking  is  concerned,  we  think  that  the  city  of 
Trenton  is  what  might  be  called  a  pressed-brick  city,  for  the 
reason  that  a  specialty  is  made  of  that  class  of  brick  by  all  the 
yards  carrying  on  business  there  (60  per  cent,  of  all  the  brick 
manufactured  in  the  city  of  Trenton  are  pressed  brick),  which 
we  think  is  the  largest  percentage  of  this  class  of  brick  made  in 
any  one  city  in  the  United  States. 

"  We  shall  now  endeavor  to  give  you  some  of  our  ideas  on 
the  making  of  pressed  brick,  ideas  which  we  have  .gained 
through  a  practical  experience  in  their  manufacture,  and  will 
cheerfully  invite  any  discussion  on  the  matter. 

SELECTING   AND   PREPARING   THE    CLAYS. "WEATHERING." 

"  First  in  order  we  will  try  and  give  you  our  ideas  on  the  se- 
lecting and  preparing  of  the  clays  or  raw  material  to  be  used  in 
the  manufacture  of  pressed  brick.  Of  course  all  sections  of  the 
country  do  not  have  just  the  right  kind  of  materials  that  will 
produce  a  first-class  pressed  brick,  and  where  clays  are  found 
suitable  for  the  purpose,  they  will  differ  very  much  in  their 
natures  in  one  locality  from  what  they  are  in  some  others,  and 
therefore  the  manufacturer  in  selecting  and  preparing  his  ma- 
terials is  compelled  to  be  governed  according  to  circumstances, 
that  is,  he  must  make  the  best  use  of  what  different  materials 
he  may  have  at  hand,  for  the  reason  that  pressed  brick  as  well 
as  other  building  brick  will  hardly  permit,  or  will  pay  well 
17 


258  BRICK,  TILES   AND   TERRA-COTTA. 

enough  to  allow  the  shipping  of  the  clay  any  great  distance. 
Now,  although  the  burning  of  pressed  brick  is  the  last  process 
which  the  clay  goes  through  before  being  finished  into  pressed 
brick,  it  is  about  the  first  step  to  be  taken  into  consideration. 
In  selecting  and  preparing  our  raw  materials  we  must  first  know 
what  the  brick  that  are  to  be  made  from  them  will  be  when 
burnt,  or  else  all  of  our  work  at  the  start  will  be  of  no  use ;  and 
I  think  all  of  you  will  agree  with  me  when  I  say  that  to  prepare 
materials  that  will  make  a  good  pressed  brick  in  a  raw  or  green 
state  is  but  very  little  trouble,  but  to  get  at  what  kind  of  ma- 
terials will  make  a  perfect  pressed  brick  after  it  has  gone 
through  the  test  of  firing  requires  much  care  and  study ;  and  we 
think  that  the  only  way,  or  at  least  the  best  way  known  to  us 
at  present  how  to  combine  materials  successfully  for  the  making 
of  good  pressed  brick  is  by  a  practical  experience,  that  is  by 
the  making  of  different  trials  and  experiments  with  whatever 
kinds  of  clay,  loam  or  sand  that  the  manufacturer  may  have  at 
his  command. 

"Of  course  a  chemical  analysis  of  clays  is  all  right  as  a 
matter,  of  theory,  but  where  so  much  raw  material  is  required 
to  be  used  as  is  the  case  in  the  manufacture  of  brick ;  I  think 
that  the  knowledge  and  experience  gained  by  practical  working 
is  by  far  the  best;  of  course  it  requires  time  and  expense  to  get 
this  kind  of  experience,  but  it  will  certainly  pay  the  manufac- 
turer the  best  in  the  long  run. 

"  Some  of  the  main  points  to  be  considered  in  combining 
materials  for  pressed  brick  is  to  get  a  combination  that  will 
stand  enough  firing  to  produce  a  brick  of  sufficient  hardness 
for  all  purposes  without  too  much  warping  or  shrinkage,  and  at 
the  same  time  to  retain  a  desirable  color,  as  we  often  find  that 
in  using  too  much  of  a  clay  that  will  fuse  or  melt  easily,  the 
brick  when  burnt  are  warped  and  crooked  and  shrunk  so  much 
that  they  will  be  of  many  different  sizes,  those  that  are  burnt 
the  hardest  being  smaller  than  those  that  are  not  burnt  so  hard, 
and  on  the  other  hand  some  material  will  stand  more  firing  and 
produce  a  brick  that  will  be  of  a  fair  color  and  keep  straight 


MANUFACTURE  OF  PRESSED 'AND  ORNAMENTAL  BRICK.      259 

and  of  full  size  when  burnt,  but  probably  they  will  not  be  as 
tough  and  strong  as  are  desired.  Thus  it  happens  very  often 
that  by  combining  two  or  more  materials  together  we  get  the 
results  for  which  we  are  trying.  There  is  such  a  wide  differ- 
ence in  materials  that  one  manufacturer  may  have  at  his  com- 
mand from  what  others  may  have,  that  there  can  be  no  set 
rule  for  the  combining  of  materials  for  pressed  brick,  that  will 
apply  to  every  locality  or  that  can  always  be  followed  with 
safety.  The  preparation  and  proper  pugging  or  tempering  of 
clays  for  pressed  brick  is  quite  an  important  matter,  but  with 
the  improved  machinery  that  has  lately  been  brought  into  use 
for  that  purpose  it  can  now  be  done  with  very  little  difficulty. 

"  The  question  of  weathering  clay  before  being  used  for  the 
manufacture  of  brick  is  a  thing  that  has  been  advocated  always 
as  beneficial.  We  claim  that  the  benefits  which  a  manufac- 
turer will  gain  by  the  weathering  of  clays  before  using  depends 
a  great  deal  upon  circumstances.  In  the  first  place,  we  do  not 
think  that  a  brick  can  be  any  better  from  having  the  clay  ex- 
posed to  the  weather  for  a  long  time  than  it  can  by  using  the 
clay  direct  from  the  bank,  providing  that  the  clay  be  thor- 
oughly worked  and  mixed  before  being  used. 

"  So  you  can  see  that  what  we  mean  by  this  is,  that  the 
weathering  of  clay  is  of  no  real  benefit  to  the  finished  article, 
but  will  only  lessen  the  labor  and  expense  of  mixing  and  pre- 
paring of  the  clay  before  use. 

"This  matter,  as  well  as  some  other  points  appertaining  to 
the  manufacture  of  pressed  brick,  must  be  governed  according 
to  circumstances.  In  some  places  the  clays  used  are  of  a  very 
stubborn  and  strong  nature,  and  will  not  yield  readily  to  the 
common  methods  used  for  tempering  and  mixing  unless  they 
are  first  exposed  to  the  weather  for  a  long  time,  and  then  they 
will  yield  very  readily  when  the  water  is  placed  upon  them  for 
the  purpose  of  soaking  and  mixing.  It  is  much  cheaper  to 
expose  material  of  this  kind  to  the  weather  than  it  would  be  to 
use  extra  machinery  for  the  purpose  of  reducing  it  to  that  state 
that,  it  can  be  worked  by  the  ordinary  methods  used  for  temper- 


26O  BRICK,  TILES   AND   TERRA-COTTA. 

ing.  The  majority  of  clays  that  are  used  for  the  manufacture 
of  pressed  brick  can  be  worked  at  a  reasonable  cost  of  labor 
and  expense  without  the  process  of  weathering,  and  for  these 
reasons  we  claim  that  it  is  much  cheaper  to  use  the  material 
direct  from  the  bank,  and  we  think  it  can  be  done  without  in 
any  way  affecting  the  quality  of  the  finished  article. 

"  There  is  one  expense  attached  to  the  weathering  of  raw 
material  to  be  used  in  the  manufacture  of  brick,  besides  the 
cost  of  the  extra  handling  which  is  necessary,  and  that  is  in  the 
percentage  of  loss  to  the  materials  by  being  exposed  a  long 
time  to  the  elements.  We  have  made  some  tests  of  what  loss 
there  is  in  weathering  clay  by  digging  it  up  in  the  early  winter 
and  letting  it  lie  until  the  next  summer  before  using  it,  which 
is  about  the  period  that  it  has  been  the  custom  for  brickmakers 
in  the  eastern  part  of  the  United  States  to  weather  their  clay, 
and  we  have  found  that  the  actual  loss  to  materials  has  been 
fully  fifteen  per  cent. 

MOULDING  THE   GLUTS. 

"  In  coming  to  the  first  crude  form  in  which  pressed  brick  are 
generally  moulded  after  selecting  and  preparing  the  clays,  we 
shall  more  particularly  speak  of  such  brick  as  they  are  gen- 
erally made  in  the  East,  that  is,  what  is  termed  a  regular  hand- 
made brick.  They  are,  as  you  all  probably  know,  first 
moulded  in  "  glut"  form  one  at  a  time  by  hand,  and  then  al- 
lowed to  dry  to  a  certain  consistence  before  they  are  re-pressed. 
We  have  found  that  the  better  we  can  have  this  first  "glut"  or 
crude  form  of  the  brick  moulded,  the  better  the  finished  article 
will  be. 

"  Many  pressed  brick  manufacturers  have  been  led  into  error 
by  supposing  that  any  way  of  getting  the  first  form  of  the 
brick  for  re-pressing  is  good  enough,  that  is,  they  will  naturally 
think  if  they  only  get  the  amount  of  clay  required  for  a  brick  in 
almost  any  shape  or  form,  it  is  all  that  is  required,  taking  it  for 
granted  that  the  press  when  it  comes  to  the  repressing  must  of 
course  make  a  brick  from  it  that  will  be  perfect  in  both  shape 


MANUFACTURE  OF  PRESSED  AND  ORNAMENTAL  BRICK.      26 1 

and  quality.  This  is  a  great  error,  for  the  reason  that  there  is 
very  little  material  from  which  we  have  ever  seen  press  brick 
made  that  would  not  show  the  defects  caused  by  improper 
moulding,  even  after  the  brick  might  be  most  carefully  re- 
pressed. 

"  One  of  the  first  qualities  that  is  required  in  a  good  press 
brick  is  for  it  to  have  a  fine  surface  or  skin  on  the  sides  and 
ends  of  the  brick,  as  they  are  the  parts  that  are  exposed  to 
view  when  laid  in  the  building. 

"  This  skin  should  be  smooth  and  uniform  and  not  broken, 
and  we  find  by  experience  that  the  only  time  to  get  a  fine  sur- 
face to  the  brick  is  in  the  first  moulding  of  the  "  glut"  brick. 
As  you  are  aware,  that  is  done  by  the  proper  application  of  a 
coating  of  moulding  sand  on  the  outward  surfaces  of  the  brick 
in  the  process  of  moulding.  That  is,  each  proportion  of  clay 
required  to  make  one  single  brick  is  thoroughly  rolled  in  fine 
moulding  sand  and  the  moulds  are  also  coated  with  it,  and  the 
sand  not  only  gives  the  brick  a  fine  skin  or  coating,  but  it  also 
causes  the  brick  to  slip  freely  from  the  moulds.  This,  I  think, 
has  been  one  of  the  main  difficulties  that  have  been  met  with  in 
making  brick  by  machinery  and  then  re-pressing  them  for  front 
brick. 

"  In  making  brick  with  what  is  termed  a  soft-clay  machine, 
the  clay,  as  a  rule,  is  forced  into  the  mould  in  a  raw  state,  and 
we  can  only  depend  on  what  sand  we  can  get  on  the  inside  sur- 
face of  the  mould  to  form  the  coating  of  the  surface  of  the 
brick  when  finished. 

"Then  again,  the  sand  that  is  generally  required  to  be  used 
in  making  brick  with  a  soft-clay  machine  in  almost  all  cases  is  too 
sharp  to  form  a  coating  to  the  brick,  for  the  reason  that  very 
sharp  sand  will  not  combine  properly  with  the  clay  to  form  the 
skin  to  the  brick.  You  will  find  that  when  too  sharp  a  sand  is 
used,  instead  of  adhering  to  the  clay  and  forming  a  smooth  un- 
broken surface  to  the  brick,  it  will  become  detached  as  the 
brick  dries  and  rub  off  very  easily,  and  of  course  leave  the 
brick  with  a  rough  and  broken  surface. 


262  BRICK,  TILES   AND   TERRA-COTTA. 

"  In  moulding  brick  with  what  is  called  a  stiff-clay  machine 
and  then  re-pressing  for  front  brick,  we  do  not  think  this  trouble 
is  met  with  to  such  an  extent,  for  the  reason  that  no  sand  at 
all  is  required  to  make  the  brick  slip,  as  the  clay  is  forced 
through  the  die  of  the  machine  in  a  square  form  called  the  web, 
and  then  cut  by  wires  into  the  individual  proportions  that  are 
required  for  each  single  brick.  By  taking  a  very  fine  sand 
(powdered  clay  would  answer  as  well)  and  applying  it  to  the 
web  of  clay  as  it  passes  from  the  die  of  the  machine,  we  think 
that  the  matter  of  coating  the  surface  of  the  brick  to  form  the 
skin  that  we  have  mentioned  can  be  accomplished  if  the  sand- 
ing is  properly  done. 

"  Now  in  giving  you  what  we  shall  only  call  our  own  ideas 
concerning  these  two  classes  of  brick  machines  that  are  most 
used  in  the  making  of  the  '  glut '  for  pressed  brick,  we  will  state 
that  we  have  never  used  any  kind  of  machine  for  the  making  of 
pressed  brick  at  our  yards,  nor  do  wre  know  of  any  ever  used 
in  Trenton,  so  you  can  see  that  we  are  not  talking  in  favor  of 
any  one  brick  machine,  nor  on  the  other  hand  do  we  condemn 
any;  but  we  have  simply  mentioned  these  facts  about  them  in 
regard  to  their  making  a  good  pressed  brick,  and  to  bring  out 
any  good  point  any  of  you  may  have  to  give  us  on  the  use  of 
brick  machines  in  the  moulding  of  (  gluts '  for  pressed  brick. 

DRYING   THE  '/  GLUTS  "  BEFORE    RE-PRESSING. 

"  The  drying  of  the  brick  before  they  are  re-pressed,  we 
think,  is  one  of  the  most  important  things  that  we  have  to 
consider  in  their  manufacture.  To  get  a  good  pressed  brick  it 
is  necessary  that  they  should  be  dried  regularly  and  not  too  fast, 
for  if  they  are  dried  too  fast  the  outside  of  the  brick  is  liable  to 
get  crusted,  while  the  middle  will  be  too  soft,  and  then  when 
they  are  re-pressed  the  corners  are  liable  to  crumble  or  not  be 
filled  out  properly. 

"  The  best  and  most  economical  way  to  dry  a  pressed  brick 
is  yet  an  open  question  to  be  determined  in  the  near  future  by 
manufacturers  in  the  East. 


MANUFACTURE  OF  PRESSED  AND  ORNAMENTAL  BRICK.      263 

"  There  has  been  little  progress  made  in  the  artificial  drying 
of  pressed  brick,  but  we  think  the  time  will  come,  and  it  cannot 
too  soon,  either,  when  the  drying  of  pressed  brick  by  artificial 
heat  will  be  accomplished  so  as  to  make  it  a  permanent  success  ; 
and  when  that  time  does  come  not  only  the  manufacturer  of 
pressed  brick  will  be  benefited,  but  hands  employed  in  their 
manufacture  will  be  benefited  fully  as  much. 

"  One  of  the  benefits  to  the  manufacturer  in  drying  pressed 
brick  by  artificial  heat  will  be  that  he  will  not  require  over 
about  one-quarter  of  the  yard  room  that  is  now  necessary  to 
dry  pressed  brick  by  the  sun  and  air,  and  the  business  can  then 
be  conducted  so  as  not  to  be  dependent  on  certain  seasons  of 
the  year,  or  subjected  to  the  annoyance  and  loss  from  storm 
and  bad  weather. 

"The  employe  will  of  course  be  benefited  by  having  em- 
ployment the  whole  year,  instead  of  having  to  depend  on  the 
weather  for  what  work  he  gets,  as  is  the  case  now. 

RE-PRESSING. 

"  The  re-pressing  of  brick  is  nbt  of  so  much  importance  as 
some  of  the  other  branches  of  the  industry,  as  we  have  already 
mentioned,  for  the  reason  that  by  using  any  reasonable  amount 
of  care  a  brick  that  has  been  well  moulded,  and  then  allowed 
to  dry  to  the  proper  consistence,  must,  of  course,  come  from 
the  re-press  in  good  form,  as  the  pressing  of  a  pressed  brick  is 
more  of  a  mechanical  operation,  and  can  be  done  with  very  lit- 
tle trouble  by  making  use  of  the  many  improvements  that  have 
been  made  in  the  hand  presses  that  are  used  for  that  purpose. 

BURNING   PRESSED    BRICK. 

"  When  we  come  to  the  final  and  most  important  part  of 
manufacture,  which  is  when  the  properly-dried  and  pressed 
brick  go  to  the  kiln  to  be  burnt,  that  is  where  a  brick-maker, 
and  especially  one  engaged  in  the  manufacture  of  pressed  brick, 
has  most  of  his  trouble  to  overcome  before  he  can  make  his 
business  a  success. 


264  BRICK,  TILES   AND   TERRA-COTTA. 

"  The  burning  of  clay  after  it  has  been  made  into  any  of  the 
different  kinds  of  articles  for  which  it  is  now  used,  either  in  the 
form  of  any  kind  of  brick  or  terra-cotta,  crockery  or  tile,  has 
always  been  a  matter  of  great  study  and  care. 

"  The  manufacturer  who  is  compelled  to  depend  on  the  firing 
of  clays  before  he  can  make  a  final  success  of  his  goods,  will 
always  have  something  more  to  learn,  no  matter  how  long  he 
may  have  been  engaged  in  the  business. 

"  A  successful  manufacturer  of  pressed  brick  after  he  has 
taken  into  consideration  all  the  benefits  he  may  have  received 
during  the  last  twenty  or  thirty  years  from  the  improvements 
in  machinery  for  the  making  or  re-pressing  of  the  brick,  or  the 
preparing  and  tempering  of  the  clay,  and  after  summing  up  the 
advantages  he  has  gained  by  these,  he  will  still  claim  that  he 
has  made  more  money  and  met  with  more  substantial  success 
to  his  business  by  careful  study  and  improvements  in  the  burn- 
ing of  the  brick  than  he  could  make  by  all  the  other  improve- 
ments combined.  If  a  careful  record  could  be  obtained  of 
what  has  caused  the  different  failures  in  brickmaking,  about 
four-fifths  of  such  failures  we  think  could  be  truthfully  attributed 
to  improper  burning. 

"  We  have  mentioned  these  facts  in  regard  to  the  burning  of 
the  pressed  brick  for  the  reason  that  we  think  it  is  the  all- 
important  question,  and  also  that  the  matter  may  be  fully  dis- 
cussed here,  so  that  we  can  all  have  the  benefits  of  the  views  of 
the  different  members  of  the  Association  on  this  subject. 

"  The  reason  why  the  proper  burning  of  the  brick  is  of  vital 
importance  in  the  business  is  that  we  have,  before  the  brick 
reaches  the  kiln,  expended  upon  it  a  very  large  proportion  of 
the  actual  cost  of  its  production,  and  notwithstanding  all  these 
expenses,  the  brick  has  no  market  value  until  it  is  burned.  In 
fact,  the  green  pressed  brick  has  no  more  commercial  value  up 
to  the  time  it  reaches  the  kiln  than  the  raw  materials  have 
while  they  are  in  the  ground.  You  can  therefore  see  by  taking 
this  view  of  it  that  the  place  for  press  brick  manufacturers  to 
make  a  sure  success  of  their  business  is  at  the  kiln. 


MANUFACTURE  OF  PRESSED  AND  ORNAMENTAL  BRICK.      265 

"  And  I  think,  gentlemen,  that  if  any  one  of  you  has  a  friend 
who  contemplates  starting  in  the  brick  business,  and  he  should 
come  to  you  for  advice  as  to  what  kind  of  a  machine  is  the 
best  for  a  pressed  brick  manufacturer  to  make  money  with  in 
the  business,  I  think  you  will  always  be  safe  by  simply  answer- 
ing '  the  kiln.' 

SETTING   THE    BRICK. 

"  The  setting  or  placing  of  the  brick  in  the  kiln  is  a  part  of 
the  work  that  we  must  depend  on  to  a  great  extent  to  have  the 
pressed  brick  well  burnt. 

"The  idea  which  has  been  gaining  ground  for  some  years 
that  brick  cannot  be  set  in  the  kiln  too  high  or  the  kiln  too 
large,  we  think  is  a  mistake.  Of  course  we  speak  now  of  the 
old  method  of  burning  brick  in  regular  old-fashioned  kilns,  or 
what  are  termed  the  Dutch  kiln.  There  are,  as  you  all  well 
know,  many  other  kinds  of  patent  kilns  that  have  been  tried 
and  are  still  in  use  in  many  parts  of  the  country ;  of  these  we 
cannot  speak,  as  we  have  had  no  experience  with  them ;  there- 
fore, our  ideas  of  them  either  onft  way  or  the  other  would  be 
of  no  particular  value  to  any  of  you. 

"  But  as  to  the  setting  of  the  brick  in  the  open-top  or  Dutch 
kilns,  we  think  that  for  burning  of  pressed  brick  a  kiln  should 
not  be  set  over  36  to  38  courses  high  in  all,  that  is  from  the 
bottom  to  the  top  of  the  kiln,  including  all  the  common  brick 
in  the  kiln  as  well  as  the  pressed  brick.  This,  we  think,  is 
about  as  high  as  they  should  be  set  to  burn  economically  and 
with  safety  to  the  pressed  brick.  Our  reasons  for  this  are  that 
we  think  the  quicker  we  can  get  the  heat  to  the  top  of  the  kiln 
the  better,  as  that  is  the  part  of  course  that  is  farthest  from  the 
fire,  and  the  hardest,  as  a  rule,  to  reach.  We  think  for  the 
same  reason  that  the  brick  should  be  set  very  open  at  the 
bottom  and  throughout  the  body  of  the  kiln  until  they  reach 
within  four  or  five  courses  of  the  top,  and  then  placed  closer  so 
as  to  hold  the  heat  when  it  reaches  that  point. 

"  As  to  the  time  required   to   burn   a  kiln  of  pressed   brick 


266  BRICK,  TILES   AND   TERRA-COTTA. 

properly,  it  will  of  course  depend  somewhat  on  the  kind  of 
materials  that  are  used  in  their  manufacture,  that  is,  as  we  have 
stated  before,  the  materials  used  in  making  pressed  brick  differ 
very  much,  and  some  clays  will  take  longer  to  burn  into  brick 
than  others,  but  we  do  think  that  all  brick  are  the  better  by 
being  burnt  just  as  quick  as  the  nature  of  the  clay  will  allow 
them  to  be  fired 

"  Some  persons  may  think  that  this  is  a  strange  doctrine  to 
advocate  in  brick  burning,  as  we  well  know  that  almost  all  of  the 
theories  that  have  ever  been  advanced  on  this  point  have  been 
to  the  effect  that  the  more  time  you  consume  in  burning  brick 
the  better  the  brick  will  be.  My  reasons  for  taking  the 
opposite  view  of  this  theory  is  that  we  think  there  is  a  certain 
amount  of  life  (as  we  might  term  it  for  want  of  a  better  name) 
contained  in  the  brick  during  the  time  it  goes  through  the  pro- 
cess of  heating,  which  we  think  should  be  taken  advantage  of 
and  used  as  a  part  of  the  burning  process.  As  an  example, 
we  will  call  your  attention  to  the  re-burning  of  brick.  There 
are  many  of  you  no  doubt  that  have  had  occasion  to  re-burn 
brick  the  second  time,  for  the  reason  of  their  having  been  burnt 
too  soft  at  the  first  firing.  We  know  that  this  has  been  done 
very  often,  not  only  by  setting  parts  of  a  kiln  with  them,  but 
we  have  seen  whole  kilns  of  salmon  brick  re-fired  the  second 
time ;  and  you  will  find  that  when  brick  are  brought  in  contact 
with  intense  heat  the  second  time  that  the  fire  does  not  act  as 
readily  upon  them  as  it  did  the  first  time,  and  while  they  may 
be  burnt  hard  enough  at  the  second  firing,  they  certainly  are 
not  as  good  as  the  brick  that  are  burnt  to  the  right  degree  of 
hardness  from  a  green  state  and  at  one  burning. 

"  Hence,  we  claim  that  when  we  consume  more  time  than  is 
actually  necessary  to  burn  a  kiln  of  brick,  that  the  kiln  becomes, 
to  a  great  extent,  somewhat  in  the  nature  of  a  brick  that  has 
come  in  contact  with  the  fire  a  second  time,  or,  in  other  words, 
you  simmer  away  and  destroy  all  the  life  which  a  brick  has  for 
fire  before  you  commence  to  burn  it,  which  not  only  adds  to 
the  expense  of  burning,  but  makes  the  brick  of  less  market 
value. 


MANUFACTURE  OF  PRESSED  AND  ORNAMENTAL  BRICK.     267 

"  As  to  our  own  experience  in  the  matter  of  burning  brick, 
we  will  say  that  the  brick-makers  of  Trenton  have  made  that 
part  of  the  business  a  study,  and  with  some  success,  as  some  of 
you  that  are  among  us  here  to-day  can  testify,  as  we  have  had 
the  pleasure  of  a  personal  visit  from  some  few  of  you  now 
present,  and  we  shall  be  pleased  at  any  time  in  the  future  to 
show  more  of  you  how  pressed  brick  are  burnt  in  Trenton,  N.  J. 

"  There  is  one  circumstance  connected  with  the  brick  busi- 
ness in  Trenton  which  has  compelled  the  manufacturer  to  make 
a  careful  study  of  burning  brick,  and  that  is,  as  before  stated, 
the  large  percentage  of  pressed  brick  that  are  produced  there 
to  the  amount  of  common  brick  made.  As  we  all  well  know 
that  good  pressed  brick  cannot  be  burnt  in  all  parts  of  an  ordi- 
nary kiln,  and  when  a  manufacturer  comes  to  making  about 
sixty  per  cent,  of  all  his  production  into  pressed  brick  he  is 
compelled  to  set  a  larger  proportion  of  them  into  each  kiln 
than  it  has  been  the  general  rule  to  do.  So  you  will  see  that 
the  proper  burning  of  the  brick  is  a  very  important  matter  to  a 
Trenton  manufacturer,  for  the  reason  that  he  has  been  to  an 
extra  expense  in  the  manufacture  df  a  very  large  proportion  of 
his  brick  before  burning. 

"  Brick-makers  in  Trenton  all  use  the  same  kind  of  kilns, 
which  are  the  ordinary  coal  kilns,  with  the  grates  running  the 
full  width  of  the  kilns.  The  arches  of  the  kiln  are  made  sta- 
tionary, instead  of  forming  them  with  green  brick  each  time  the 
kiln  is  set.  This  is  done  more  to  save  making  so  many  com- 
mon brick  to  form  the  arches  with,  than  for  any  other  purpose. 

"  The  time  occupied  in  burning  a  kiln  in  Trenton  is  about 
four  days  and  three  nights,  or  eighty-four  hours  in  all.  This 
includes  the  full  time  for  firing,  from  the  time  the  match  is  ap- 
plied until  the  kiln  is  closed  up  and  finished,  and  we  think  there 
are  more  kilns  that  are  burnt  there  in  a  less  time  than  we  have 
stated  than  there  are  that  over-run  the  time  specified.  The 
brick  are  all  burnt  with  anthracite  coal,  no  other  kind  of  coal 
being  used. 

"We  have  kept  a  record  in  our  yard  for  several  years  of  the 


268  BRICK,  TILES   AND   TERRA-COTTA. 

cost  of  the  fuel  for  burning  our  brick,  and  we  have  here  a 
a  statement  covering  seven  years,  which  we  will  read  to  you, 
and  you  can  then  compare  it  with  others  that  may  be  made 
here,  as  the  matter  of  fuel  for  burning  brick  is  a  very  important 
question,  and  we  want  to  have  all  the  light  thrown  on  the  sub- 
ject that  we  can  obtain. 

COST   OF    FUEL. 

"  1 88 1,  number  of  brick  burnt  per  ton  of  coal,  4,1 13  ;  cost  of 
fuel  per  1 ,000  brick,  $  i  .03  ;  price  of  coal  per  ton  delivered,  $4.2  5 . 

"  1882,  number  of  brick  burnt  per  ton  of  coal,  4,280;  cost  of 
fuel  per  1,000  brick,  $.97  ;  price  of  coal  per  ton  delivered,  $4.15. 

"  1883,  number  of  brick  burnt  per  ton  of  coal,  4,274;  cost  of 
fuel  per  1,000  brick,  $.97  ;  price  of  coal  per  ton  delivered,  $4.15. 

"  1884,  number  of  brick  burnt  per  ton  of  coal,  4,551  ;  cost  of 
fuel  per  1,000  brick,  $.91  ;  price  of  coal  per  ton  delivered,  $4.15. 

"  1885,  number  of  brick  burnt  per  ton  of  coal,  4,530;  cost  of 
fuel  per  1,000  brick,  $.86;  price  of  coal  per  ton  delivered,  $3.90. 

"  1889,  number  of  brick  burnt  per  ton  of  coal,  4,632  ;  cost  of 
fuel  per  1,000  brick,  $.89 ;  price  of  coal  per  ton  delivered,  $4.25. 

"  1890,  number  of  brick  burnt  per  ton  of  coal,  4,267 ;  cost  of 
fuel  per  1,000  brick,  $.97  ;  price  of  coal  per  ton  delivered,  $4.15. 

"  Making  the  average  cost  for  seven  years  for  fuel  to  burn 
I, OCX)  brick  94  6-10  cents  per  1,000.  And  the  average  number 
of  brick  burnt  with  one  ton  of  coal  for  seven  years  4,378." 

The  following  is  from  a  paper  read  by  Mr.  C.  W.  Raymond, 
of  Dayton,  Ohio,  before  the  Ohio  Brick,  Tile  and  Drainage 
Association,  held  in  the  city  of  Columbus,  Ohio,  February  25, 
1891.  The  paper  is  entitled  "  Pressed  and  Ornamental  Brick." 

"I  strenuously  advocate  the  advisability  of  having  certain 
days  on  which  to  '  strike  out '  brick  for  re-pressing.  Special 
care  can  better  be  given  to  the  preparation  of  the  clay;  the 
machinery,  belting,  molds,  presses,  etc.,  can  be  cleansed  and 
oiled  for  the  occasion ;  dry  clay  or  hard  particles  removed  from 
the  machine  or  pug  mill ;  the  drying  floor,  pallets  and  racks  be 
swept  and  having  removed  all  dirt  and  dust  from  them ;  the 


MANUFACTURE  OF  PRESSED  AND  ORNAMENTAL  BRICK.       269 

brick  machine  can  be  run  at  a  slower  speed  to  admit  of  time 
being  taken  to  give  the  best  results  in  handling ;  in  fact,  the  rush 
and  hurry  incident  upon  making  large  numbers  of  common 
brick  can  be  avoided.  Again,  in  striking  out  brick  for  re- 
pressing it  is  necessary  that  an  extra  amount  of  clay  should  be 
contained  in  them.  First,  to  compensate  for  condensation 
given  them  by  pressure.  Second,  pressed  brick  when  laid  in 
the  wall  require  a  much  smaller  mortar  joint  than  common 
ones ;  hence  to  bond  with  them  properly  they  must  be  thicker, 
therefore  larger  molds  are  required.  These  and  other  reasons 
present  themselves  why  it  is  advantageous  to  have  stated  days 
or  times  for  this  work. 

"  I  would  not  advise  my  friends  to  attempt  to  make  pressed 
brick  without  satisfying  themselves  that  their  material  is  suit- 
able, either  in  itself  or  susceptible  of  advantageous  combination. 
This  should  be  determined  by  an  actual  test  by  a  practical 
burner.  A  chemical  analysis  is  of  inestimable  value  in  deter- 
mining the  presence  of  alkalies  or  other  impurities  which  cause 
so  much  unsightly  efflorescence  in  many  of  our  fine  fronts. 
The  novice,  however,  need  not  be  ^discouraged  if  his  first  trial 
does  not  '  pan  out.'  If  it  does  not  indicate  that  he  has  made  a 
'  rich  find,'  additional  experimenting,  combination  or  chemical 
treatment  may  later  on  develop  the  fact  that  he  has  struck  '  pay 
dirt.' 

"The  manner  of  preparing  the  clay  and  striking  out  the 
brick  for  making  pressed  brick  is  identical  with  that  of  making 
common  brick,  except,  perhaps,  the  precautionary  measures 
that  are  taken  to  insure  the  very  best  results.  It  seems  unneces- 
sary for  me  to  describe  a  process  so  well  known  to  you  all. 
Weathering  is  usually  advisable.  It  is  a  great  help  in  the  tem- 
pering or  pugging  of  the  clay,  as  the  assimilation  caused 
thereby  lightens  the  work  on  the  machinery  and  produces  a 
thorough  mixture  of  the  strata. 

"  It  is  important  first  of  all  that  the  clay  be  free  from  stones, 
roots,  and  all  foreign  substances.  Judicious  work  of  the  pit- 
men in  '  weeding'  out  the  largest  of  these  at  the  clay-bank  is 


2/0  BRICK,  TILES   AND   TERRA-COTTA. 

commendable.  Frequent  stoppages  of  the  machinery  are 
avoided,  and  its  liability  to  breakage  reduced  to  a  minimum. 

"  If  stones  abound  in  any  quantity  they  should  be  separated 
from  the  clay  by  a  roller  crusher,  or  if  they  be  not  large  and  of 
a  limestone  formation,  a  disintegrator  or  pulverizer  to  reduce 
them  will  answer.  In  the  latter  contingency  the  crushed  stones 
form  an  integral  part  of  the  clay  and  are  worked  up  with  it. 
Experience  alone  can  demonstrate  whether  they  deteriorate  its 
quality  or  are  otherwise  objectionable. 

"  The  pugging  process  which  follows  is  one  of  importance,  as 
upon  its  thoroughness  depends  largely  the  uniformity  of  your 
material.  A  pug-mill,  in  addition  to  the  one  which  usually 
forms  part  of  the  machine,  relieves  the  latter  of  excessive  strain 
and  better  prepares  the  clay  for  all  future  work  upon  it ;  in  fact, 
by  its  use  the  clay  is  thoroughly  prepared  before  reaching  the 
machine,  whose  only  remaining  duty  is  to  strike  out  the  brick. 

"  In  sanding  the  moulds  for  use  with  the  machine,  a  fine  sand 
giving  a  rich,  red  color,  is  required.  Where  this  is  not  obtain- 
able, good  results  can  be  had  by  using  moulding  sand,  or  the 
dust  from  the  rattle,  procurable  in  any  foundry.  Sieve  through 
a  very  fine  sieve,  not  less  than  No.  60. 

"  Tempering  clay  by  a  wheel  and  moulding  by  hand  is  still 
followed  in  many  localities.  Results  from  this  method,  although 
slow,  have  always  proven  satisfactory  and  profitable. 

"  What  machine,  if  any,  is  best  adapted  for  re-pressed  brick? 
I  have  seen  very  excellent  brick  made  on  all  machines,  hence 
I  do  not  advocate  any  kind  of  machine  or  any  special  mode  of 
manufacture.  The  machine  is  but  the  agent  for  putting  the  gluts 
into  shape  ;  for  producing  the  necessary  amount  of  clay  in  each. 
This,  I  claim,  can  be  done  successfully  by  any  of  the  good  ma- 
chines now  on  the  market,  other  conditions  being  favorable. 
As  to  the  machine  best  adapted  to  the  manipulation  of  any 
special  clay,  it  is  a  question  to  be  determined  only  by  actual 
experience  or  trial  with  it. 

"The  re-press,  although  a  small  machine,  plays  a  no  less 
important  part  in  the  production  of  fine  brick  than  larger  and 


MANUFACTURE  OF  PRESSED  AND  ORNAMENTAL  BRICK.     271 

more  expensive  ones.  The  press  should  at  all  times  be  kept 
clean  and  its  working  parts  oiled.  I  commend  the  method  in 
use  in  some  of  our  yards  which  requires  the  pressman  to  clean 
and  oil  the  press  thoroughly  at  the  completion  of  each  day's 
work. 

"The  dies  of  the  press  should  be  frequently  dressed  or 
re-lined,  and  the  plungers  packed  out  to  fit  snugly  therein ; 
perfect  brick  may  not  be  expected  from  an  imperfectly  con- 
structed or  partly  worn  die,  as  each  brick  will  take  on  all  the 
imperfections  of  the  press  die. 

"I  am  frequently  asked  how  much  pressure  is  required  to 
re-press  a  brick.  I  have  never  yet  attempted  to  answer  this 
question,  and  will  not  do  so  here,  but  will  say:  When  the 
edges  and  corners  of  the  brick  are  perfectly  developed,  the  end 
sought  by  re-pressing  is  attained.  Multiplied  tons  of  pressure 
will  not  do  more. 

"  A  skilled  workman  who  can  exercise  judgment  in  handling 
and  working  the  press  should  operate  it.  When  the  press  is  in 
operation  the  die  should  be  wiped  off  with  an  oiled  rag  or 
brush  after  each  brick  is  pressed,  or  as  often  as  required  to 
prevent  adhesion  of  the  brick  to  the  die.  An  oil  suitable  for 
this  purpose  is  composed  of  coal  oil  one  part  and  lard  oil 
three  parts,  or  coal  oil  and  engine  oil  in  the  same  proportion, 
or  coal  oil  and  rancid  butter ;  the  latter  being  warm  and  mixed 
makes  an  excellent  lubricant. 

"The  little  paddles  by  which  the  brick  are  removed  from 
the  die  after  pressing  must  present  a  smooth  and  even  surface 
to  the  brick,  and  should  be  rubbed  off  occasionally  to  remove 
accumulations  of  clay,  or  redressed  when  their  surfaces  be- 
come uneven  by  wear. 

"The  drying  sheds  I  consider  as  necessary  to  the  produc- 
tion of  good  pressed  brick,  as  the  press  and  other  fixtures. 
By  their  use  the  sun  is  excluded,  the  air  currents  are  con- 
trolled, and  you  are  better  able  to  produce  brick  of  an  even 
temper  throughout,  without  which  good  results  in  re-pressing 
are  impossible.  Brick  dried  in  the  sun  or  out  of  doors,  dry 


2/2  BRICK,  TILES   AND   TERRA-COTTA. 

hastily  and  unevenly;  their  inner  portions  remain  soft  and 
mushy  while  their  surfaces  are  crusty,  and  their  corners  and 
edges  dried  prematurely;  thus  rendering  them  unfit  for  the 
re-press.  The  brick  must  dry  slowly  and  regularly.  This 
result  can  be  obtained  by  the  drying  shed. 

"  The  drying  shed  can  be  arranged  with  racks  similar  to  an 
outdoor  rack  for  drying.  They  should  be  built  wide  enough 
apart  to  allow  the  trucks  and  presses  to  be  wheeled  between 
them,  and  not  so  high  but  that  the  pallets  of  brick  can  be  re- 
moved from  the  top  shelves  easily.  Boards  running  length- 
wise with  the  shed  can  be  hinged,  forming  an  easy  manner  of 
regulating  the  air  currents.  A  moderate  degree  of  artificial 
heat  can  be  introduced  to  advantage. 

"  When  the  gluts  are  in  a  proper  condition  for  re-pressing, 
they  are  taken  from  the  racks,  picked  up  carefully  one  by  one, 
and  their  faces  smoothed  over  by  hand  or  rubbed  lightly  with 
a  soft  brush.  They  are  then  laid  on  the  plunger  of  the  re-press 
and  subjected  to  uniform  and  gentle  (not  over)  pressure. 
After  their  expulsion  from  the  press  die  they  are  carefully 
picked  up  by  an  off-bearer  between  two  thin  paddles  and  re- 
placed again  in  their  position  on  the  racks.  Frequently,  how- 
ever, they  are  hacked  one  above  another  until  four  or  five  high 
and  allowed  to  dry  in  this  manner,  or  again  they  are  removed 
on  trucks  to  a  drying  floor  where  they  are  allowed  to  remain 
unmolested  until  ready  for  the  kiln.  In  any  event  it  is  advis- 
able to  handle  the  brick  after  pressing  as  little  as  possible  until 
they  become  dry. 

"  A  most  significant  step  in  the  production  of  fine  front  brick 
is  setting.  This  should  be  done  by  competent  men  who  will 
exercise  judgment  and  care  that  the  importance  of  the  work 
demands.  Setting  as  done  by  the  Royal  Brick  Company,  of 
Bridgeport,  Ohio,  is  as  follows:  (I  mention  this  company  as 
one  of  several  with  whose  manner  of  working  I  am  familiar, 
and  who  have  been  able  to  attain  a  great  degree  of  proficiency 
in  their  special  line.) 

"  They  use,  I  believe,  an  up-draft  kiln.     After  the  arches  are 


MANUFACTURE  OF  PRESSED  AND  ORNAMENTAL  BRICK.      2/3 

turned  the  courses  are  leveled  the  entire  width  of  the  kiln ;  so 
much  importance  do  they  attach  to  this  that  a  spirit  level  is 
used  for  the  purpose.  The  brick  must  be  set,  not  only  per- 
fectly level,  but  plumb.  The  settling  heat,  therefore,  if  the 
burning  is  uniform,  is  more  likely  to  bring  all  down  regularly 
and  even,  which  to  a  great  extent  will  prevent  sliding,  warping 
or  twisting.  Their  brick  are  set  one  face  exactly  above  an- 
other, neither  projecting  at  the  ends  or  sides.  The  courses 
do  not  extend  to  the  walls  of  the  kiln,  but  are  separated  there- 
from by  several  lengths  of  common  brick. 

"They  commence  to  set  pressed  brick  as  near  above  the  top 
of  the  arches  as  possible,  and  extend  about  fifteen  to  eighteen 
courses  high  in  a  kiln  of  forty  to  forty-five  high  including  all. 
This  they  think  is  as  many  as  can  be  burned  profitably. 

"  I  would  not  advocate  either  the  setting  of  the  entire  kiln  so 
high  or  the  placing  of  so  large  a  number  of  courses  of  pressed 
brick  therein.  In  many  cases  it  would  result  disastrously,  giv- 
ing an  unusual  per  cent,  of  salmon  or  under  colored  brick  by 
reason  of  setting  too  high  on  the  one  hand,  or  hard  or  over- 
colored  brick  by  proximity  to  tl^e  arches  on  the  other.  This 
question,  however,  can  only  be  determined  in  each  case  by 
actual  results  of  burning. 

"  Brick  should  be  thoroughly  dry  before  setting.  The 
courses  should  be  set  open  at  the  bottom  and  closer  as  they 
near  the  top  of  the  kiln,  and  should  be  burned  as  quickly  as 
the  nature  of  your  clay  will  permit.  These,  I  believe,  are 
points  about  which  no  controversy  exists. 

"  A  matter  of  serious  concern  to  the  manufacturer,  and  one 
which  sustains  a  greater  relation  to  profit  and  loss,  to  success 
or  failure,  is  burning.  Whatever  importance  may  be  attached 
to  this  in  the  production  of  common  brick,  it  is  doubly  so  in 
that  of  pressed  and  ornamental. 

''When  the  brick  have  arrived  at  that  state  of  their  produc- 
tion where   they  are  ready  to  be  burned,  all   labor  has  been 
expended  upon  them.     A  kiln  of  brick  ready  to  fire  frequently 
represents  from  $1,200  to  $1,500  invested  capital.     It  matters 
18 


274  BRICK,  TILES   AND   TERRA-COTTA. 

not  what  expenditure  of  money  has  been  made  in  purchasing 
the  most  improved  machinery  and  devices  to  insure  the  very 
highest  results  in  manipulating  your  clay,  it  matters  not  how 
thoroughly  your  clay  may  have  been  prepared,  or  how  care- 
fully or  deftly  your  brick  may  have  been  handled  from  the 
machine  to  the  racks,  from  the  racks  to  the  press,  from  the 
press  to  the  drying  floor,  and  from  the  drying  floor  to  the  kiln, 
all  is  lost  unless  the  burning  is  successful. 

"Does  it  not  behoove  us  then  to  use  the  most  improved 
systems  of  burning?  Should  not  the  highest  skill  of  the 
burner's  art — for  it  is  an  art — be  called  into  requisition? 

"  The  kind  of  fuel  required  and  amount  thereof  consumed, 
the  time  required  in  burning,  etc.,  are  largely  questions  to 
be  determined  by  experience,  and  depend  upon  the  chemi- 
cal properties  and  peculiarities  of  your  clay,  and  should  com- 
mand your  best  study  and  thought.  I  can  find  no  fixed  rule 
applicable  to  all  cases.  The  main  point  in  burning  pressed 
brick  is  to  obtain  a  uniform  color,  which  can  be  done  only  by 
uniformity  of  heat  and  an  even  combustion  in  all  parts  of  the 
kiln.  While  these  conditions  should  exist  in  all  burns,  they 
are  especially  essential  to  the  successful  production  of  fine 
pressed  brick. 

"When  opening  the  kiln  remove  the  common  brick  down  to 
the  top  course  of  the  pressed  brick,  sweep  or  brush  these 
courses  carefully,  remove  the  press  brick  two  at  a  time,  toss  in 
pairs  and  lay  on  a  spring  barrow.  Use  lath  between  the 
layers,  and  load  about  forty  brick  to  the  barrow.  Great  care 
must  be  exercised  in  handling  the  brick  to  prevent  chipping  or 
spalling.  The  faces  must  not  come  in  contact  one  with  the 
other,  or  an  ugly  scratch  or  mark  will  be  the  result. 

"  A  dry,  roomy  and  light  stock  shed  should  be  arranged  with 
ten  or  twelve  stalls  or  apartments  for  the  various  shades  of 
brick.  To  this  shed  the  brick  are  wheeled,  where  they  are 
taken  charge  of  by  the  sorter,  one  whose  duty  it  is  to  arrange 
them  according  to  their  various  colors  and  shades.  A  man 
with  clear  perception,  a  keen  eye,  and  excellent  judgment, 


MANUFACTURE  OF  PRESSED  AND  ORNAMENTAL  BRICK.      2/5 

should  fill  this  important  office.  If  not  graded  by  an  artistic 
eye  according  to  their  delicate  shades,  they  would  but  present 
a  spotted  and  unsightly  appearance  to  the  beholder  when 
shown  in  comparison  in  the  walls  of  a  fine  building. 

"This,  I  believe,  completes  a  description  of  the  machinery, 
appurtenances  and  methods  of  making  and  handling  success- 
fully re-pressed  brick.  I  might  have  entered  more  largely  into 
details,  but  these  are  well  known  to  you  all.  The  points  I  have 
suggested  are  general,  and  will  apply  to  any  system,  and  if  ad- 
hered to,  cannot  fail  to  be  of  value. 

"  In  making  a  brick  of  fine  quality  for  front,  few  realize  the 
importance  of  properly  preserving  the  faces  of  the  brick  from 
contamination  or  abrasion.  It  is  a  prevalent  but  fallacious 
opinion  that  anything  will  make  a  pressed  brick,  that  the  press 
will  remove  the  imperfections,  square  the  brick,  and  make  an 
artistic  and  beautiful  piece  of  work  from  an  ill-shaped  glut  of 
clay.  Such  is  not  the  case.  Abrasions,  finger  marks,  paddle 
marks,  etc.,  once  given  to  the  face  of  the  brick  cannot  be  re- 
moved by  the  press ;  in  fact,  it  is  my  conviction,  based  upon 
observation,  that  the  higher  finish  and  beauty  the  surfaces  of 
your  pressed  brick  are  susceptible  of,  the  more  sensitive  they 
are  to  these  defects. 

"  Another  point  to  which  I  would  direct  your  attention  is 
the  growing  disposition  to  produce  large  numbers  of  pressed 
brick  per  day.  Many  of  our  manufacturers  require  from  4,000 
to  5,000  brick  to  be  re-pressed  per  day  by  two  men,  using  one 
hand  press.  Excessive  quantities  of  pressed  brick  can  only  be 
produced  at  the  expense  of  that  more  desirable  property, 
quality. 

"  In  Philadelphia,  the  Mecca  of  the  pressed  brick  industry, 
but  1,500  to  i, 800  brick  are  produced  per  day,  each  glut  being 
struck  out  singly  and  by  hand  in  a  steel  or  brass  mould.  While 
this  manner  of  working  seems  to  the  average  Westerner  some- 
what primitive,  yet  the  world-wide  reputation  and  high  market 
value  of  Philadelphia  brick  would  indicate  that  the  standard  of 
excellence  which  they  have  attained  is  due  to  their  fine  quality, 


276  BRICK,  TILES   AND   TERRA-COTTA. 

which   can   only   be   had   by  the   exercise   of   great   care   and 
patience  in  their  production. 

"  I  find  I  have  omitted  all  reference  to  the  manufacture  of 
ornamental  brick,  and  the  great  improvements  which  have 
been  made  of  recent  years  for  their  manufacture,  whereby 
from  one  to  two  thousand  elaborate  and  beautiful  designs  are 
made  per  day,  where  formerly  but  as  many  hundred  were  pro- 
duced. Nor  have  I  referred  to  the  advent  of  the  power  press, 
whose  coming  promises  to  revolutionize  old  and  slower 
methods  of  re-pressing  brick. 

"  A  few  years  ago  the  manufacturer  who  would  have  pro- 
posed to  handle  by  automatic  mechanism  so  delicate  a  form  as 
a  soft  brick  would  have  been  voted,  putting  it  mildly,  peculiar. 
Now  we  find  the  power  press  used  in  many  of  our  large  yards, 
working  with  almost  marvelous  results.  However,  as  they,  as 
well  as  manners  and  forms  of  working  in  connection  therewith, 
are  yet  subjects  of  study  and  development,  I  will  content  my- 
self with  this  brief  reference. 

"  An  aphorism  in  vogue  among  chemists  says,  '  In  medicine 
quality  is  of  first  importance.'  The  same  may  be  aptly  applied 
to  pressed  brick.  Quality  is  of  first  importance.  It  is  from 
this  they  obtain  their  high  market  value.  Without  the  care 
and  time  necessary  to  give  your  pressed  brick  their  well  de- 
fined lines,  their  smooth  velvety  surfaces,  their  symmetrical 
proportion,  in  fact,  without  a  desire  to  attain  the  IDEAL,  they 
are  frequently  of  little  more  value  than  the  common  ones,  and 
their  enhanced  worth  will  not  justify  the  expenditure  of  time 
and  money  necessary  for  their  production. 

"  A  story  well  known  by  you  all  is  told  of  an  old  darkey  who 
was  called  to  the  bedside  of  his  dying  master,  and  informed 
that  he  might  have  any  three  wishes  gratified  that  he  might 
name.  The  old  fellow  was  nonplussed  at  such  a  beneficent 
and  unexpected  offer,  but  when  pressed  for  an  answer,  replied, 
'  Well,  Massa,  I  want  first,  all  the  whiskey  I  can  drink.  I  want 
second,  all  the  clothes  me  and  the  old  woman  can  wear,'  and, 
rather  doubting  the  scope  of  his  first  request,  said,  '  well,  Massa, 


MANUFACTURE  OF  PRESSED  AND  ORNAMENTAL  BRICK.      277 

if  it  makes  no  difference  to  you,  I'll  take  a  little  more  whiskey/ 
Applying  the  logic  of  this  story  to  the  subject  in  hand,  if  asked 
the  prerequisite  to  the  successful  production  of  fine  pressed 
brick,  I  would  say  CARE,  and  if  asked  the  next  in  importance, 

I  would  say  A  LITTLE  MORE  CARE." 

ORNAMENTAL   BRICK. 

Ornamental  brick  are  usually  made  in  the  same  manner  as 
fine  pressed  brick ;  the  quantities  produced  for  a  day's  work  are 
less,  but  vary  with  the  size  and  complications  of  the  designs. 

In  the  year  1884  the  Perfection  Press  was  invented  and 
patented  by  Mr.  C.  W.  Raymond,  of  Dayton,  O.,  a  novel  and 
simple  machine  with  great  power,  in  construction  deviating  from 
the  similarity  between  those  of  its  class  then  existing. 

Mr.  Raymond  had  made  the  wants  of  the  brick-maker  a  study 
for  years,  having  previously  invented  several  useful  and  valuable 
improvements  for  their  use.  The  Perfection  Press  was  largely 
the  result  of  his  experience  and  investigation. 

The  press,  which  is  illustrated  in  Fig.  69,  is  constructed  en- 
tirely of  iron  and  steel,  the  finest  inaterial  only  being  used.  For 
the  dies,  which  require  hardness  and  a  high  finish,  a  special 
grade  of  steel  is  manufactured.  All  parts  are  capable  of  ad- 
justment. The  entire  work  of  pressing  the  brick  and  removing 
it  from  the  die  is  accomplished  with  one  motion  of  the  lever ; 
this  important  point  facilitates  the  work  and  allows  the  brick 
to  be  handled  much  more  rapidly  than  where  2  or  3  levers  are 
employed. 

Any  size  or  shape  mould  can  be  used  upon  one  press,  hence 
a  great  variety  of  work  can  be  done  with  this  press,  such  as  red 
brick,  fire  brick,  paving  blocks,  roofing  tile,  etc. 

It  can  be  adjusted  to  press  any  brick  of  any  thickness  by  the 
adjustable  platen  at  the  top. 

Its  great  power  is  also  a  feature  rendering  it  valuable  on  the 
heavier  grades  of  work. 

The  special  feature  of  the  press,  however,  and  one  which  has 
worked  a  great  change  in  the  manner  of  making  ornamental 


2/8 


BRICK,  TILES   AND   TERRA-COTTA. 


brick  and   terra-cotta,   is   its   adaptation    to   that  work.     The 
ornament  is  used  upon  the  top  plunger,  which  after  pressing 

FIG.  69. 


RAYMOND'S  PERFECTION  PRESS. 


the  brick  entirely  lifts  itself  from   it.     All  annoyance  of  loose 
plates  in  the  bottom  of  the  press  dies  required  by  other  presses 


MANUFACTURE  OF  PRESSED  AND  ORNAMENTAL  BRICK.   279 

is  avoided,  and  the  finest  designs  are  produced  almost  as  read- 
ily as  common  brick. 

The  ornamental  plates  are  made  in  brass  from  designs  fur- 
nished by  the  manufacturer  of  the  press  or  submitted  by  the 
purchaser,  and  can  be  used  upon  each  press  in  endless  variety. 

It  has  been  demonstrated  that  the  best  results  in  ornamental 
work  can  be  obtained  where  great  pressure  is  employed,  there- 
by solidifying  the  block,  imparting  to  the  surface  that  lustrous, 
velvety  appearance  so  much  sought  for,  pressing  the  most 
obscure  parts  into  prominence,  and  giving  to  each  block  uni- 
formity of  size  and  figure  absolutely  essential  to  architectural 
effect. 

Mr.  Raymond,  by  his  patented  Perfection  Press  and  system 
of  working  soft  clay  into  ornamental  and  terra-cotta  designs, 
has  reduced  a  heretofore  complicated  process  to  exactness  and 
simplicity,  opened  up  an  inexpensive  and  exhaustless  field  of 
manufacture  to  the  brick-maker,  and  made  it  possible  for 
artistic  results  to  be  obtained  by  those  of  ordinary  means  and 
comparatively  little  experience. 

In  the  manufacture  of  ornamental  brick  and  tiles,  by  the 
use  of  a  re-press,  the  "  stiff-mud  process  "  can  be  successfully 
employed  for  the  following  reasons :  The  clay  being  stiff 
enough  to  re-press  as  soon  as  run  into  the  right  form  and  size — 
either  4x8,  8x8,  10x10,  12x12,  or  any  other  desired  size — the 
labor  of  handling  is  avoided.  The  clay,  having  no  sand  on  its 
surface,  takes  a  clean,  sharp,  well-defined  impression  from  the 
matrix. 

The  following  is  a  brief  description  of  the  method  of  the 
manufacture  of  ornamental  brick  and  tiles  by  the  "  stiff-mud 
process :" 

When  the  clay  blank  or  "  glut "  is  in  the  right  condition  to 
re-press,  it  is  dusted  on  the  face  side  which  is  to  receive  the 
impression,  and  this  side  is  placed  upon  the  matrix,  which  is  a 
thin  plate  with  the  reverse  of  the  pattern  which  you  desire 
upon  one  side.  This  matrix  or  mould  is  in  the  bottom  of  the 
press-box,  in  some  presses.  Manufacturers  have  various  appli- 


280  BRICK,  TILES   AND   TERRA-COTTA. 

ances  for  making  ornamental  work.  With  some  the  plate  is 
placed  in  the  bottom  of  the  press,  and  others  have  the  plate  on 
top  of  the  brick  while  pressing. 

In  the  first  case  the  brick  is  lifted  off  from  the  plate  after 
pressing,  and  in  the  other  the  plate  is  removed  before  the 
pressed  brick  is  lifted  entirely  from  the  mould. 

A  third  method  is  to  have  the  matrix  fastened  to  the  cap, 
top-plate,  or  follower,  as  the  case  may  be,  according  to  the 
kind  of  press  you  are  using,  and  when  the  cap  is  lifted  off,  the 
matrix  is  lifted  with  it,  and  then  the  brick  is  lifted  from  the 
press  without  the  danger  of  distortion,  such  as  the  other 
methods  present,  in  attempting  to  remove  the  plate  from  the 
brick.  Each  of  these  processes  has  its  respective  advantages, 
and  the  manufacturer  must  use  such  a  one  as  to  him  seems 
best. 

To  manufacture  to  the  best  advantage,  three  presses  should 
be  used,  one  for  large  tile,  one  for  brick,  and  one  for  edge- 
work,  but  one  press  may  be  made  to  answer  by  changing  the 
press-box  and  follower  plates. 

Various  substances  are  employed  to  prevent  the  matrix  ad- 
hering to  the  clay.  Oil  is  generally  used  for  this  purpose,  but 
in  designs  having  great  relief  or  depressions  it  is  sometimes 
almost  impossible  to  remove  the  matrix  from  the  ware  without 
injury;  others  use  dust  of  some  kind — very  fine  sand — which 
will  burn  a  good  color ;  pulverized  coal,  charcoal,  etc.,  are  also 
used. 

Brick-dust  passed  through  a  bolting  cloth  is  the  very  best 
thing  that  can  be  utilized — burns,  of  course,  the  same  color  as 
the  clay,  and  produces  a  rich,  velvety  surface,  and  the  brick 
never  stick. 

When  the  ornament  required  is  very  bold,  it  is  best  to  re- 
press twice. 

After  the  first  pressing,  which  should  not  be  very  hard,  the 
brick  is  dusted. 

When  it  has  shrunk  just  enough  to  drop  easily  into  the 
mould  box,  the  superfluous  dust  is  blown  off,  either  by  a 


MANUFACTURE  OF  PRESSED  AND  ORNAMENTAL  BRICK.      28  I 

bellows  or  lung  power,  and  then  pressed  the  second  time 
firmly.  The  subsequent  treatment  consists  in  carefully  remov- 
ing any  superfluous  clay  from  the  edges,  a  little  hand-rubbing, 
and  careful  drying  and  burning. 

The  main  thing  to  insure  success  in  ornamental  work,  either 
with  mouldings  or  pressed  work,  is  thorough  preparation  of  the 
clay. 

It  should  have  sand  or  "grog"  enough  in  it  to  prevent  undue 
shrinkage,  or  liability  to  crack,  in  drying  or  burning.  For  the 
higher  classes  of  ware,  clay  that  had  been  once  burned  and  pul- 
verized should  be  used  to  the  extent  of  about  25  per  cent. 

The  Northwestern  Terra-Cotta  Works,  of  Chicago,  111.,  buy 
all  the  bats  from  the  Anderson  Pressed-Brick  Company  that 
they  have  to  spare,  and  grind  them  up  by  a  slow-motion  large- 
diameter  crusher.  One  crusher  crushes  the  bats  to  the  size  of 
a  hickory-nut.  They  then  pass  through  another  crusher,  and 
everything  is  ground  fine.  The  works  named  use  crushed  brick 
to  the  extent  of  40  or  50  per  cent,  in  some  of  their  wares,  and 
always  with  good  results. 

Mr.  Batley,  in  speaking  of  t}ie  use  of  pulverized  bricks, 
or  "  grog,"  for  preventing  the  excessive  shrinking  of  clay  dur- 
ing the  process  of  manufacture,  said  :  "  In  South  Wales  we  were 
engaged  in  making  enameled  glazed  brick,  fire-brick  and 
sewer-pipes,  and  when  we  came  to  the  question  of  anything 
over  half  an  inch  to  three-fourths  in  thickness,  it  used  to  warp 
and  crack  all  to  pieces,  and  it  soon  put  me  to  thinking  what 
to  do  to  prevent  the  clay  from  cracking ;  and  while  there  en- 
gaged in  making  24-inch  sewer-pipe,  I  have  had  to  use  as 
much  as  60  per  cent,  of  '  grog,'  and  the  clay  is  not  in  existence, 
as  far  as  my  experience  goes,  that  cannot  be  prevented  from 
cracking." 

After  the  "  grog,"  or  pulverized  brick,  has  been  mixed  with 
the  green  clay,  the  mixture  should  be  allowed  to  remain  for  one 
week  in  the  tempering  pit  after  being  wet,  and  as  long  after 
pugged  the  first  time  as  possible,  before  being  run  into  mould- 
ing or  for  pressed  ware. 


282  BRICK,  TILES   AND   TERRA-COTTA. 

Success  in  ornamental  brickmaking,  as  in  all  other  manufac- 
turing enterprises,  is  determined  largely  by  attention  to  details. 

Fig.  70  shows  a  front  view  of  the  Panel  Re-press,  which  is 
manufactured  by  the  Frey-Sheckler  Co. 

FIG.  70. 


This  was  the  first  and  is  the  only  machine  of  its  class  manu- 
factured in  the  United  States.  It  is  especially  designed  to  meet 
the  wants  of  brick  manufacturers  producing  a  high  grade  of  brick 
for  enameled  glazing,  where  it  is  very  essential  to  have  all  of  the 
brick  of  an  exact  thickness.  It  is  also  adapted  for  pressed  and 
ornamental  brick  when  a  fine  finish  of  product  is  required.  This 
machine  is  constructed  on  new  and  scientific  principles,  as  will  be 
seen  by  the  illustration.  The  shafts  are  made  of  steel.  The  gears 
are  extra  heavy  and  of  new  design.  The  machine  is  mounted 
on  an  extra  heavy  cast-iron  box  bed.  It  is  simple  in  construc- 
tion, easily  accessible,  and  no  parts  liable  to  get  out  of  order. 
All  of  the  gears  and  mechanical  movements  are  so  arranged  as 
to  be  entirely  free  from  clay,  etc.,  so  as  to  prevent  wear.  The 
feed  and  discharge  of  the  brick  in  this  machine  is  strictly  auto- 


MANUFACTURE  OF  PRESSED  AND  ORNAMENTAL  BRICK.      283 

matic.  Machines  of  this  class  from  abroad  do  not  enjoy  this  in- 
genious mechanical  device,  but  must  be  stopped  at  the  pressing 
of  each  brick  in  order  that  the  same  may  be  removed  from  the 
mould.  This  machine  is  supplied  with  a  friction-clutch  pulley, 
so  as  to  enable  the  operator  to  start  or  stop  the  machine  at 
will.  Capacity  from  6,000  to  10,000  highly- finished  brick  per 
day;  weight  of  machine  4,500  pounds. 

Fig.  71  shows  a  front  view  of  the  Eagle  Double  Mould  Re- 

FIG.  71. 


press,  which  is  manufactured  by  the  Frey-Sheckler  Co.  It  is 
intended  for  re-pressing  front  brick,  roadway  paving  brick, 
fire  brick,  etc.,  and  has  a  capacity  of  15,000  to  28,000  every 
ten  hours. 


CHAPTER  IX. 


KILNS. 
TEMPORARY    KILNS. 

THE  question  of  what  method  of  burning  to  adopt  or  what 
class  of  kilns  to  employ  is  one  which  must  be  largely  governed 
by  local  circumstances.  If  the  works  are  not  located  near  clay 
fields  which  promise  to  yield  clay  in  sufficient  quantities  to 
warrant  the  erection  of  permanent  kilns,  then,  of  course,  the 
only  thing  to  be  done  is  to  use  temporary  kilns  or  "  clamps." 

Ordinarily  the  fuel  in  temporary  brick-kilns  or  clamps  is 
placed  within  the  arches  either  directly  upon  the  ground,  when 
wood  is  used;  or  upon  grates  extending  through  the  entire 
length  of  the  arches.  This  mode  of  firing  is  objectionable,  for 
the  reason  that  it  is  commonly  very  difficult  to  regulate  the  fire 
so  as  to  produce  brick  of  uniform  color  and  strength. 

The  kiln  shown  in  Figs.  72,  73,  74,  75  and  76,  which  is  that 
of  Mr.  Wm.  H.  Brush,  of  Buffalo,  N.  Y.,  is  designed  to  remedy 
the  difficulties  and  objections  named. 

FIG.  72. 


Fig.  72  is  a  sectional  elevation,  showing  an  arch  of  a  brick- 
kiln provided  with  the  Brush  improvements.  Fig.  73  is  a  plan 
view  of  two  arches.  Fig.  74  is  a  front  view,  showing  one  arch 
in  front  elevation,  and  one  in  cross-section.  Fig.  75  is  a  rear 
view,  and  Fig.  76  a  horizontal  section  of  the  fire-door. 

(284) 


KILNS. 


285 


A  represents  the  arch  of  green  brick  set  up  in  the  usual 
manner.  B  are  the  frames  of  the  fire-doors,  arranged  in  the 
outer  walls  of  each  arch  in  the  ordinary  manner.  C  is  a  fire- 
grate, preferably  about  five  feet  in  length,  arranged  within  each 
arch,  at  each  end  thereof,  as  clearly  shown  in  the  drawing.  The 

FIG.  73. 


ra* 


grates  C  are  supported  upon  bars  d  d1  resting  upon  the  brick 
of  the  ash-pit  D,  which  latter  is  preferably  composed  of  old  or 
burned  brick.  E  is  an  inclined  plate  or  apron  hinged  or  hung 
to  the  rear  grate-bar  d\  as  clearly  represented  in  the  draw- 
ings, and  made  of  the  same  widtjji  as  the  ash-pit,  so  as  to  pre- 
vent the  cold  air  in  the  ash-pit  from  entering  the  arch,  except 


FIG.  74. 


FIG.  75. 


through  the  burning  fuel  upon  the  grate  C.  The  aprons  E 
incline  toward  the  ash-pit  door  F,  so  as  to  cause  the  ashes  and 
cinders  dropping  upon  the  aprons  to  slide  forward  toward  the 
ash-pit  door ;  and  the  hinging  of  the  aprons  to  the  grate-bars 
enables  the  front  ends  of  the  aprons  to  be  raised,  so  as  to  per- 


286  BRICK,  TILES   AND   TERRA-COTTA. 

mit  access  to  the  fuel  placed  upon  the  ground  between  the 
grates  C  C. 

G  is  the  fire-door,  hinged  to  the  frame  B,  and  provided  with 
vertical  slots  or  openings  g,  which  are  opened  and  closed  by  a 
sliding-plate  gl,  in  the  manner  of  an  ordinary  register. 

H  is  a  protecting-plate,  arranged  on  the  inner  side  of  the  fire- 
door  G,  and  connected  thereto  by  stay-bolts  h  in  the  usual 
manner :  i  are  vertical  slots  or  openings,  arranged  in  the  plate 
H  in  such  a  manner  that  solid  portions  of  plate  H  are  opposite 
the  openings  g  of  the  fire-door  G,  and  the  openings  i  opposite 
the  solid  portions  of  the  fire-door.  This  construction  of  the 
protecting-plate  H  causes  the  air-currents  entering  through  the 
openings  g  of  the  fire-door  to  impinge  against  the  solid  portion 
of  the  plate  Ht  which,  being  kept  at  a  very  high  temperature  by 
the  fire  upon  the  grate,  heats  the  air  before  it  enters  the  arch, 
thereby  preventing  the  brick  from  becoming  checked. 

The  grates  C  may  be  charged  with  wood  or  coal,  and  the 
space  C1  between  the  grates  is  preferably  charged  with  wood  or 
coke.  By  admitting  a  strong  air-current  through  the  fire-doors 
G,  the  flame  and  hot  gases  are  driven  from  the  grates  C  toward 
the  center  of  the  kiln,  and  the  combustion  of  the  fuel  between 
the  grates  is  accelerated.  Upon  closing  the  damper  in  the  fire- 
door  Gy  the  hot  gases  from  the  grates  C  rise  perpendicularly 
through  the  arch,  and  the  combustion  of  the  fuel  between  the 
grates  is  retarded.  Upon  raising  the  ends  of  the  aprons  E,  the 
ashes  can  be  raked  out  from  the  space  between  the  grates,  and 
new  fuel  can  be  supplied  thereto  without  interfering  with  the 
fuel  upon  them,  while,  by  supporting  the  front  ends  of  the 
aprons  in  a  greater  or  less  elevated  position,  the  combustion  of 
the  fuel  in  the  space  between  the  grates  can  be  regulated  with- 
out affecting  the  combustion  of  the  fuel  upon  the  grates. 

It  is  obvious  from  the  foregoing  description  that  these  im- 
provements, which  are  readily  and  cheaply  applied  to  kilns  of 
ordinary  construction,  give  control  over  the  fires  in  all  parts  of 
the  arch,  thereby  enabling  the  brick  to  be  burned  to  a  more 
uniform  color  than  in  clamps  as  ordinarily  constructed. 


KILNS.  287 

The  entire  fire-surface  being  arranged  within  the  arch,  the  heat 
developed  by  the  fuel  is  fully  utilized,  and  loss  from  radiation, 
while  not  of  course  fully  prevented,  is  to  a  great  extent  curtailed. 

UP   AND   DOWN   DRAFT   KILNS. 

Kilns  for  burning  brick  and  tiles  thoroughly  and  economically 
are  often  constructed  with  an  up  and  down  draft  which  connect 
with  the  same  fire  chamber  and  are  usually  provided  with  flues 
arranged  beneath  a  perforated  floor  and  which  communicate 
with  the  main  chimney  and  outlets  on  top  of  the  kiln,  the 
flues  from  the  fire  chamber  being  provided  with  suitable  dampers. 

The  kiln  shown  in  Fig.  77  is  the  invention  of  Mr.  Willis  N. 

FIG.  77. 


Graves,  of  the  Hydraulic  Brick  Co.,  St.  Louis,  Mo.,  and  it  con- 
sists, first,  in  the  arrangement  of  the  flues  beneath  the  floor  of 
the  kiln ;  and,  secondly,  in  preventing  the  products  of  combus- 
tion taking  the  shortest  course  from  the  tops  of  the  vertical 
flues  to  the  flues  beneath  the  floor. 

Fig.  77  is  the  front  elevation  with  a  small  portion  of  the  es- 
cape-flue broken  away.  Fig.  78  is  a  vertical  section  taken  on 
line  2  2,  Fig.  77,  showing  one  side  of  the  kiln  filled  with  brick, 


288 


BRICK,  TILES   AND   TERRA-COTTA. 


and  the  other  side  empty.  Fig.  79  is  a  horizontal  section  taken 
on  line  3  3,  Fig.  78,  with  part  of  the  floor  of  the  kiln  broken 
away,  to  show  the  distributing-flues  beneath. 

A  represents  the  outer  walls  of  the  kiln,  strengthened  by  ties 
B,  as  usual,  and  having  the  customary  lining  C,  of  fire-clay. 


D  represents  the  kiln  or  brick-chamber,  with  a  floor  E,  with 
passages  Ft  forming  a  communication  with  flues  beneath  the 
floor.  The  floor  preferably  consists  of  tile  made  from  fire-clay, 
supported  on  walls  or  ribs  G,  which  form  the  main  flue  for 
each  fire-chamber,  or  each  set  of  fire-chambers  where  two 
series  are  used,  as  shown,  and  these  main  flues  are  subdivided 
by  the  intermediate  wall  G,  which  does  not  quite  extend  to  the 
sides  of  the  chamber,  as  shown  in  Fig.  79,  thus  forming  small 
distributing-flues  H  H1  H*  H\  Of  these  three  intermediate 
walls,  the  outer  ones  have  inturned  ends  H*,  so  that  as  much 
heat  is  deflected  into  the  two  outer  flues  H  H*,  as  passes 
directly  into  the  two  central  flues  H1  ff*.  We  have  shown  a 
series  of  fire-chambers  /,  at  each  side  of  the  kiln  as  the  pre- 
ferred form ;  but  one  series  only  may  be  used. 


KILNS. 


289 


/'  represents  the  grate-bars  of  the  fire-chambers  and  J  the 
doors  thereto. 

K  represents  the  ash-pits. 

The  flues  H  H1  H*  H'A  communicate  with  a  transverse  flue 
Z,  which  connects  with  the  chimney  or  uptake  M.  The  com- 
munication between  the  chimney  and  flue  L  is  regulated  or 
•entirely  closed,  as  desired,  by  a  damper  N. 

Each  fire-chamber  is  provided  with  a  flue  (9,  leading  to  or 
near  the  top  of  the  kiln-chamber.  These  flues  can  be  closed 
by  dampers  P. 

FIG.  79. 

B 


Q  are  chimneys  or  outlets  on  top  of  the  kiln,  preferably  one 
for  each  pair  of  fire-chambers,  where  two  series  are  used,  and 
these  outlets  can  be  regulated  or  closed  by  means  of  dampers  R. 

The  operation  of  the  kiln  is  as  follows :  Supposing  it  is  first 
desired  to  have  the  heat  and  products  of  combustion  pass  from 
the  top  of  the  kiln  chamber  down  through  the  mass  of  brick, 
the  flues  H  H1  H1  H*  are  closed  by  pieces  of  brick  and  refuse 
matter  thrown  in  through  the  fire-chambers,  the  dampers  P  of 
the  flues  O  opened,  the  dampers  R  of  the  chimneys  Q  are 
19 


290  BRICK,  TILES   AND   TERRA-COTTA. 

closed,  and  the  damper  N  of  the  chimney  M  is  opened.  The 
fires  then  being  started,  the  heat  and  products  of  combustion 
will  pass  up  through  the  flues  O,  down  through  the  mass  of 
brick,  through  the  openings  F  into  the  flues  H  H1  H'1  //3,  and 
from  thence  through  the  transverse  flue  L  to  the  uptake  or 
chimney  M,  as  shown  by  full  arrows,  Fig.  78. 

When  a  down  draft  is  used  it  is  important  that  some  means 
be  employed  to  prevent  the  heat  and  products  of  combustion 
from  taking  the  shortest  course  from  the  tops  of  the  flues  0  to 
the  flues  H  Hl  H*  //3,  to  avoid  everburning  the  brick  next  to 
the  flues  O,  and  to  cause  an  equal  burning  of  the  brick  through- 
out the  kiln.  Furthermore,  as  the  brick  are  being  burned  they 
shrink,  forming  a  flue  between  them  and  the  sides  of  the  kiln- 
chamber,  down  which  the  heat  and  products  of  combustion 
would  be  drawn.  In  order  to  avoid  these  difficulties  the  in- 
ventor places  tiles,  of  suitable  length,  with  their  lower  ends 
resting  upon  the  upper  edge  of  the  outer  walls  of  the  flues  0, 
and  their  upper  ends  resting  upon  the  brick  as  shown  in  Fig. 
78.  Thus  the  heat  and  products  of  combustion  are  compelled 
to  pass  up  over  the  tile  before  they  can  descend.  As  the  tile 
would  not  rest  well  if  placed  directly  upon  the  tops  of  the  semi- 
circular flues  O,  the  inventor  first  places  blocks,  S1,  of  fire-clay 
on  top  of  the  flues,  covering  the  V-shaped  spaces  between  the 
flues,  as  shown  in  Fig.  79.  The  inner  corners  of  the  blocks 
are  cut  off,  concave  shape,  so  as  not  to  obstruct  the  openings 
of  the  flues.  A  common  brick  S2  can  be  placed  between  the 
ends  of  the  blocks  S1  to  give  a  uniform  height  to  the  tile  5. 
One  of  the  blocks  S1  is  shown  removed  in  Fig.  79. 

T  represents  peep-holes.     (See  Fig.  78.) 

Then,  when  an  updraft  is  desired,  the  flues  //",  H*>  H2,  H3  are 
opened  by  the  obstruction  being  removed,  as  by  means  of  an 
instrument  introduced  through  the  fire-chambers,  the  dampers 
R  of  the  chimneys  Q  opened,  the  dampers  P  of  the  flues  O 
closed,  and  the  damper  N  of  the  chimney  M  closed.  The  heat 
and  products  of  combustion  then  pass  from  the  fire-chambers 
to  the  distributing  flues  H,  H1,  H2,  H3,  through  the  passages  or 


KILNS.  291 

openings  F,  and  up  through  the  mass  of  brick,  escaping  through 
the  chimneys  Q.  The  draft  can  thus  be  changed  with  very 
little  trouble  as  many  times  as  desired  during  the  burning  of  a 
single  kiln  of  brick.  The  updraft  is  shown  by  dotted  arrows, 
Fig.  78,  on  one  side  of  the  figure,  the  downdraft  being  shown 
on  the  other  side  by  full  arrows,  as  stated. 

The  kiln  which  has  just  been  described  can  be  used, to  ad- 
vantage in  the  burning  of  fire-clay  wares  as  well  as  for  burning 
common  brick. 

CONTINUOUS    KILNS. 

The  principle  of  the  continuous  kiln  is  ( I )  to  use  the  heat 
contained  in  the  ready-burnt  brick  for  heating  the  atmospheric 
air  supporting  the  combustion,  and  (2)  to  use  the  heat  passing 
away  from  the  fire  for  heating  the  green  brick  yet  to  be  burned. 

The  first  attempt  to  burn  brick  continuously  was  the  railway 
kiln  exhibited  at  the  Paris  Exposition  in  1857.  It  ls  not  cer~ 
tain  who  was  the  inventor  of  that  kiln,  whether  Collas,  Bovie, 
or  who  else.  The  railway  kiln,  however,  did  not  prove  a  suc- 
cess, either  in  Germany,  by  Mr.  Book,  or  in  England,  by  Mr. 
Foster.  We  also  know  of  cases  in  America  where  the  railway 
kiln  was  tried,  but  likewise  without  success,  the  brick  coming 
out  of  the  kiln  being  "  uniformly  pale."  This  was  in  1867,  at 
the  brickyard  of  Barnard  &  Harvey,  at  Hestonville,  on  the 
Pennsylvania  Railroad,  Philadelphia,  where  a  railway  kiln  was 
in  use  in  connection  with  a  Chambers  machine.  Again,  in 
1892,  at  the  works  of  The  Anderson  Pressed  Brick  Co.,  Chi- 
cago, 111. 

In  the  railway  kiln  a  train  of  platform  cars  loaded  with  brick 
was  slowly  moved  by  means  of  a  screw  (worm),  or  hydraulic 
pump  through  a  long  straight  tunnel,  in  the  middle  of  which 
the  fire  was  burning ;  from  the  fire  the  loaded  brick  moved 
toward  the  end  of  the  tunnel,  cooling  down  while  in  motion. 
The  draught  of  air  in  the  tunnel  went  in  the  opposite  direction, 
the  air  entering  where  the  burned  brick  left  the  tunnel,  passing 
through  the  fire  and  escaping  to  the  chimney  at  the  other  end, 
where  the  cars  loaded  with  green  brick  entered  the  tunnel. 


292  BRICK,  TILES   AND   TERRA-COTTA. 

THE    HOFFMANN    KILN. 

In  the  year  1859  the  first  Hoffmann  kiln  was  erected  in  the 
city  of  Stettin,  Prussia,  and  in  a  few  years  100  of  these  kilns 
were  erected  in  Germany,  Austria,  England,  etc.  To-day  a 
very  large  number  of  Hoffmann  kilns  are  in  operation  all  over 
the  world,  burning  brick,  including  the  finest  paving-brick, 
terra-cptta,  roofing-tiles,  etc.  In  the  United  States  there  are 
only  about  a  dozen  genuine  Hoffmann  kilns ;  the  first  was 
erected  at  Carbon  Cliff,  Rock  Island  County,  111.,  in  the  year 
1866. 

In  the  Hoffmann  kiln  the  brick  are  not  moved  during  the 
process  of  burning,  as  in  the  railway  kiln ;  on  the  contrary,  they 
are  set  into  the  burning  chamber  as  in  old-fashioned  kilns,  and 
the  fire  is  passed  through  them  horizontally,  leaving  burned 
brick  behind.  The  burning  chamber  of  the  Hoffmann  kiln 
consists  of  an  endless  tunnel  of  an  annular  shape,  either  circu- 
lar, or  elliptic,  or  oblong  in  plan.  This  endless  tunnel  is  suc- 
cessively filled  with  green  brick,  and  after  the  fire  has  passed 
through,  leaving  the  burned  brick  behind,  they  are  successively 
taken  out  when  sufficiently  cooled  down ;  soon  afterward  they 
are  replaced  by  green  brick.  It  takes  from  ten  to  sixteen  days 
for  the  fire  to  make  a  round  in  the  Hoffmann  kiln ;  during  the 
same  time  the  whole  kiln  is  once  filled  with  green  brick,  and 
once  emptied. 

It  is  not  possible  in  the  Hoffmann  or  any  other  form  of  con- 
tinuous kiln  to  avoid  the  production  of  a  proportion  of  soft 
brick,  nor  is  it  possible  to  obtain  satisfactory  results  in  the  use 
of  such  kilns  in  burning  face  and  front  brick.  Continuous  kilns 
are  especially  adapted  for  burning  common  brick  with  the  least 
possible  expenditure  for  cost  of  fuel ;  but  it  is  an  open  question 
whether  the  interest  on  the  large  amount  of  capital  necessary 
to  build  such  kilns,  together  with  the  greater  wear,  tear,  and 
depreciation,  and  the  extra  cost  for  loading  the  brick  upon 
wheelbarrows,  and  removing  them  from  the  chambers  of  such 
kilns,  does  not  more  than  counterbalance  the  saving  of  fuel. 

This  is  especially  true  in  the  United  States,  where  fuel  is  not 


KILNS.  293 

so  much  an  item  of  cost  as  it  is  in  England  and  Continental 
Europe,  in  which  countries  the  cost  of  constructing  such  kilns 
is  also  much  less,  and  where  the  cost  of  labor  for  removing  the 
brick  on  barrows  from  the  kilns  is  also  less  than  in  America. 
Another  drawback  in  the  use  of  continuous  kilns  is  the  fact, 
although  there  is  certainty  of  being  able  to  burn  the  brick  in 
them  during  all  seasons  of  the  year,  there  is  no  certainty  that 
the  manufacturer  can  at  all  times  be  able  to  haul  brick  from 
his  yard,  as  the  weather  may  not  allow  it,  and  the  buildings  for 
which  he  contracts  to  furnish  the  brick  may  not  be  in  condition 
to  require  the  material  only  at  certain  times. 

In  our  own  experience  we  remember  that,  after  having  made 
contracts  with  the  U.  S.  Government  to  furnish  in  one  year 
17,000,000  brick  for  the  City  Hall  and  other  public  buildings 
in  Washington  City,  we  seriously  contemplated  building  two 
Hoffmann  kilns  on  our  yard ;  but  were  deterred  from  so  doing 
because  of  the  uncertainty  of  being  able  to  haul  the  brick  at  all 
times  from  our  works.  Some  days  we  could  deliver  from 
100,000  to  125,000  brick  per  day  to  the  buildings,  the  large  area 
of  dumping  ground  around  the  buildings  allowing  this,  and  then 
for  three  or  four  days  after  heavy  rains  it  would  be  almost  im- 
possible to  deliver  any  brick  from  the  yards  because  of  the 
inclement  weather  and  impassable  condition  of  the  roads. 

Our  conclusion  was,  if  we  built  the  Hoffmann  Kilns  and  went 
to  the  expense  of  wheeling  the  brick  on  barrows  from  the  kilns 
and  hacking  them  in  the  yard  until  such  times  as  they  could 
be  rapidly  hauled  to  the  buildings  during  favorable  weather, 
or  during  periods  when  there  would  occur  delays  in  setting  the 
stone-work  or  the  iron-beams  of  each  of  the  stories,  that  this 
loss  alone  would  more  than  neutralize  the  saving  of  fuel  and 
labor  resulting  from  the  use  of  such  kilns. 

In  the  United  States  it  is  not  at  all  a  question  of  being  edu- 
cated up  to  the  use  of  the  Hoffmann  or  any  other  form  of  con- 
tinuous kiln.  The  real  drawback  to  their  use  is  that  the 
interest  on  the  large  capital  required  to  build  such  kilns,  added 
to  cost  of  wear,  tear,  depreciation,  and  repairs,  and  the  in- 


294  BRICK,  TILES   AND   TERRA-COTTA. 

creased  cost  of  setting  the  brick  in  them,  and  the  cost  of  labor 
for  hauling  the  brick  in  barrows  from  the  kilns  and  hacking 
them  in  piles  and  re-delivering  them  to  the  carts  and  wagons, 
is  much  greater  with  us  in  America  than  in  Europe,  where 
these  kilns  are  in  use  in  large  numbers,  and  where  they  can  be 
built  and  operated  with  profit. 

The  English  as  well  as  the  German  brick  have  a  volume  of 
about  132  cubic  inches  (size  of  English  brick  9^x4^x2^ 
inches;  size  of  German  brick  9^x4^x2^  inches).  For 
burning  1000  ordinary  building  brick  of  this  size  in  old- 
fashioned  kilns,  on  an  average  900  pounds  of  coal  are  required, 
the  quantity  depending  on  the  nature  of  the  clay  as  on  the 
quality  of  the  coal.  The  American  brick  is  of  smaller  size ; 
the  ordinary  building  brick,  in  New  York,  for  instance,  having 
a  volume  of  hardly  eighty  cubic  inches.  The  quantity  of  coal 
required  for  burning  these  brick  is  proportionately  less,  requir- 
ing only  about  one  ton  of  coal  to  burn  about  4000  brick  of  this 
size,  in  old-fashioned  kilns.  One  ton  of  coal  costs  in  America 
about  $3  ;  the  coal  for  burning  1000  brick  in  America,  there- 
fore, costs  about  $0.75.  According  to  these  figures,  the  coal 
for  burning  1000  brick  in.  Europe  in  old-fashioned  kilns  cost 
about  $1.80.  The  market  price  of  brick  per  1000  is  about  the 
same  in  Europe  as  in  America,  common  building  brick,  on  an 
average,  selling  at  $6  per  1000;  therefore,  in  America,  the 
fuel  required  for  burning  in  old-fashioned  kilns  only  represents 
about  12^/2  per  cent.,  while  in  Europe  it  represents  30  per 
cent,  of  the  market  price  of  brick.  This  difference  is  caused 
partly  by  the  difference  in  the  size  of  the  American  brick, 
compared  with  the  European,  but  is  partly  offset  by  the  low 
wages  paid  in  Europe  compared  with  those  paid  in  America. 

From  the  foregoing  it  is  evident  that  any  saving  in  fuel  is  of 
much  more  importance  to  the  European  brickmaker  than  to 
the  American.  It  is  natural,  therefore,  that  nearly  all  en- 
deavors to  reduce  the  quantity  and  cost  of  fuel  required  for 
burning  brick  have  originated  in  Europe.  The  Americans,  on 
the  other  hand,  direct  their  energy  and  inventive  genius  chiefly 


KILNS.  295 

to  lessening  the  cost  of  the  labor  in  making  and  handling  the 
brick,  especially  through  the  use  of  labor-saving  machinery. 

Mr.  Guthrie,  a  master  mechanic  of  Manchester,  England, 
claims  to  have  invented  a  modification  of  the  Hoffmann  kiln  in 
this  respect — that  the  fuel  is  generated  into  gas  in  furnaces  on 
the  outside  of  the  apartment  in  which  the  brick  are  contained ; 
then  the  brick  are  burned  with  the  product  of  combustion, 
therefore  giving  a  good  face  brick  in  all  the  apartments, 
wherein  the  main  objection  to  the  Hoffmann  kiln  is  obviated 
by  producing  good  face  brick. 

One  of  these  Guthrie  kilns  is  in  successful  operation  at  the 
works  of  the  Columbus  Brick  and  Terra-Cotta  Company,  of 
Columbus,  Ohio. 

There  is  now  no  valid  patent  existing  in  the  United  States 
upon  the  Hoffmann  kiln. 

In  England  and  on  the  Continent  of  Europe  the  Hoffmann 
kilns  are  commonly  built  with  either  twelve  or  fourteen  cham- 
bers, twelve  chambers  answering  all  purposes  where  the  brick 
are  thoroughly  dried  before  going  into  the  kiln.  But  when 
setting  direct  from  the  machine,  as  in  the  semi-dry  process,  not 
less  than  fourteen  chambers,  and  even  sixteen  with  some  clays, 
are  preferable. 

•As  the  climate  is  so  much  warmer  in  summer  in  the  United 
States  than  in  England,  these  kilns  should  have  not  less  than 
fourteen  chambers  in  the  one  case,  and  sixteen  in  the  other. 
The  reason  is  this : 

First,  in  the  semi-dry  process,  in  order  to  be  safe  from  crush- 
ing down  as  a  result  of  too  rapid  drying,  the  setting  should  be 
at  least  six  chambers  ahead  of  the  burning.  Between  the  cham- 
bers, in  which  the  setters  are  at  work,  and  from  which  the 
drawers  are  taken  out,  there  should  be  three  vacant  chambers, 
or  it  will  be  too  hot  for  men  to  work  in  the  summer;  and  be- 
tween the  chamber  from  which  the  brick  are  being  taken  out 
and  the  chamber  just  finished  firing,  there  should  be  not  less 
than  three  chambers  cooling — if  four,  so  much  the  better  every 
way.  By  this  it  will  be  seen  that  sixteen  chambers  are  needed ; 


296  BRICK,  TILES   AND   TERRA-COTTA. 

besides,  it  is  more  economical,  inasmuch  as  the  air  necessary  to- 
bum  the  coal  as  it  is  put  in  through  the  top  has  farther  to 
travel  through  the  hot  brick,  and  consequently  its  heat  is  inten- 
sified in  proportion,  and  so  on  the  other  side,  in  firing,  every 
particle  of  heat  is  utilized ;  so  much  so  that  it  is  possible  to 
stand  in  the  smoke-chamber,  at  the  bottom  of  the  shaft,  with- 
out inconvenience  from  either  heat  or  smoke. 

Secondly,  where  brick  are  dried  before  setting  in  the  kiln, 
fourteen  chambers  will  do,  still  leaving  the  same  vacancies  be- 
tween setters  and  drawers  in  summer,  but  the  same  advantages 
accrue  on  the  ground  of  economy,  as  in  the  case  of  semi-dry 
process.  With  these  kilns  you  can  use  coal  that  cannot  be  used 
in  any  other,  and,  if  available,  gas ;  or  oil  is  as  applicable  as  to 
any  other  kiln.  As  to  the  men,  a  man  accustomed  to  good 
setting  in  the  ordinary  kiln  soon  becomes  proficient  with  these 
kilns.  The  setting  must  be  done  well  and  uniformly,  and  the 
man  professing  to  set  more  than  ten  thousand  per  day  himself 
is  not  the  man  for  the  business  in  these  kilns.  What  is  needed 
is  good  workmanship,  and  not  bustling;  the  two  qualifications 
are  never  found  combined. 

FIRING   THE    HOFFMANN    KILN. 

This  department,  of  course,  needs  skill,  and  it  is  sometimes 
more  easy  to  train  a  green  hand  than  an  old  burner  always 
accustomed  to  the  old-fashioned  kilns.  The  work  is  much 
lighter,  but  requires  somewhat  closer  attention,  inasmuch  as  the 
firing  is  done  with  a  small  scoop,  holding  about  two  pounds  of 
coal,  and  not  a  shovel.  The  coal  dust  is  dropped  through 
apertures  in  the  top  of  the  kiln,  and  distributed  among  the 
brick  in  its  descent  to  the  bottom  flues  formed  in  the  setting, 
for  the  purpose  of  draft  to  the  cross  flue  at  the  end  of  the  cham- 
ber (this  flue  is  also  formed  in  the  setting)  and  leading  into 
the  main  flue  connected  with  the  shaft.  In  the  hands  of  a 
skillful  and  careful  man,  brick  can  be  burnt  as  uniform  and 
good  as  in  any  other  kiln  in  existence,  and  certainly  much 
cheaper,  to  say  nothing  of  the  advantage  accruing  therefrom  in 
winter. 


KILNS.  297 

With  some  forms  of  material  it  is  found  impracticable  to 
burn  brick  with  the  old-fashioned  open  kiln.  The  Fish  Pressed 
Brick  Company,  of  Columbus,  Ohio,  manufactures  a  brick 
made  of  two-thirds  shale  and  one-third  clay,  ground  in  a  pan 
and  pressed  by  the  Whittaker  Dry-Press  Machine.  It  was 
found  impracticable  to  burn  these  brick  in  the  old-fashioned 
kiln.  The  company  consequently  built  a  continuous  kiln  hav- 
ing 14  chambers,  with  a  stack  over  100  feet  in  height.  The 
brick  are  taken  directly  from  the  machine  and  set  in  the  kiln. 
The  chambers  are  fed  with  coal-slack  or  dust ;  while  one  kiln 
is  burning,  the  water-smoke  is  steaming  off  three  or  four  cham- 
bers. The  heat  can  be  controlled  so  as  to  burn  the  best  fire- 
brick or  the  most  tender  red  brick. 

THE    DUEBERG    KILN. 

We  may  mention  two  other  systems  of  continuous  kilns — the 
Dueberg  kiln  and  the  Mendheim  kiln ;  the  former  is  a  mod- 
ification of  the  Hoffmann  kiln.  The  green  brick  are  placed  on 
platform  cars  and  those  are  run  into  the  burning  chamber,  as 
in  the  railway  kiln  already  mentioned.  The  burning  chamber 
of  the  Dueberg  kiln,  however,  forms  a  continuous  circuit  of 
rectangular  shape,  in  plan  similar  to  the  shape  of  many  Hoff- 
mann kilns.  The  cars  are  at  rest  in  the  burning  chamber  dur- 
ing the  process  of  burning,  being  drawn  out  of  the  kiln  one  by 
one  after  the  burning  is  finished  and  the  brick  have  become 
sufficiently  cool.  The  fire  travels  around  in  the  Dueberg  kiln 
exactly  in  the  same  manner  as  in  the  Hoffmann  kiln ;  coal  as 
well  as  gas  may  be  used  for  firing.  The  principal  object  in 
constructing  this  kiln  was  to  obviate  the  labor  of  setting  and 
taking  out  the  brick,  to  be  done  inside  of  the  hot  arched  burn- 
ing chamber,  as  in  the  Hoffmann  kiln  as  well  as  in  other 
arched  kilns,  which  must  be  artificially  lighted,  even  in  day- 
time. 

THE   MENDHEIM    KILN. 

The  Mendheim  kiln  consists  of  a  combination  of  a  series  of 
arched  burning  chambers,  connected  with  each  other  by  flues, 


298  BRICK,  TILES    AND   TERRA-COTTA. 

so  as  to  form  a  complete  circuit.  These  kilns  are  fired  by  gas 
and  the  fire  proceeds  from  one  chamber  to  another,  passing 
through  the  flues,  thus  traveling  around  similarly  as  in  the 
Hoffmann  kiln.  The  progress  of  the  fire,  however,  is  much 
slower  in  the  Mendheim  kiln,  on  account  of  its  being  com- 
pelled to  pass  through  the  flues,  the  area  of  which  is  much 
smaller  than  that  of  the  burning  chambers.  For  this  and  other 
reasons  the  Mendheim  kiln  does  not  afford  the  same  economy 
in  fuel  as  the  Hoffmann  kiln. 

REGENERATIVE    KILNS. 

The  objects  of  all  late  improvements  in  the  regenerative 
kilns  are  to  thoroughly  mix  the  air  and  gas  burned  in  such 
kilns  and  to  effect  a  better  diffusion,  regulation,  and  equaliza- 
tion of  the  heat  obtained  from  their  combustion. 

These  objects  are  best  effected  by  constructing  in  the  walls 
of  adjacent  kilns  duplex  hollow  spaces  or  flues,  the  alternating 
portions  of  the  opposite  sides  of  which  have  slits  or  perfora- 
tions formed  therein,  so  as  to  enable  the  heated  products  of 
combustion  to  be  passed  or  discharged  from  the  lowest  part  of 
one  kiln  into  the  lowest  part  of  the  next  kiln — that  is  to  say, 
the  kiln  which  is  being  heated  preparatory  to  being  fired. 
These  flue-spaces  are  provided  with  vertical  or  horizontal 
dampers,  so  as  to  shut  off  the  communication  between  the 
kilns,  the  slits  or  perforations  in  the  flue-spaces  effecting  the 
improved  diffusion.  In  place  of  forming  such  flues  in  the  walls 
of  the  adjacent  kilns,  flues  may  be  formed  in  the  brick-work 
outside  the  wall,  in  which  case  the  air  descends  some  distance 
below  the  floor  of  the  kiln,  where  it  passes  through  ports, 
regulated  by  dampers,  into  a  still  lower  flue,  from  which  it 
escapes  through  slits  or  perforations  formed  in  the  lower  part 
of  the  walls  into  the  burner  or  chamber,  or  opening,  wherein  it 
mixes  with  the  gas.  For  the  purpose  of  admitting  either  hot 
air  into  the  upper  part  of  the  kilns  from  an  adjacent  kiln,  or 
for  the  purpose  of  admitting  cold  air  to  the  upper  part  of  a 
kiln  being  fired,  a  similar  flue — that  is  to  say,  either  duplex  or 


KILNS. 


299 


single — is  provided  with  dampers  and  with  slits  or  perforations 
in  its  opposite  sides  in  the  walls  at  or  near  to  the  upper  part 
of  the  kilns.  Either  hot  or  cold  air  is  admitted  through  these 
upper  flues  and  slits  or  perforations,  when  the  air  admitted  at 
the  lower  part  of  the  kilns  with  the  gas  may  be  either  deficient 
in  quantity  to  produce  complete  combustion,  or  when  the  tem- 
perature of  a  kiln  at  its  upper  part  may  be  either  too  high  or 
too  low.  In  place  of  making  the  flues  duplex,  with  slits  or 
perforations,  as  before  described,  they  may  be  made  single, 
with  one  side — namely,  that  through  which  the  discharge 
takes  place — constructed  with  one,  two,  or  more  larger  open- 
ings in  lieu  of  slits  or  perforations  above  or  at  a  level  with  the 
bottom  of  the  kiln,  and  with  slits  or  perforations  at  the  oppo- 
site side. 

The  regenerative  principle  just  described   may  also  be  ap- 
plied to  calcining- kilns  and  other  analogous  apparatus. 

THE   DUNNACHIE    KILN. 

Mr.   James    Dunnachie,   of   the    Glenboig    Union    Fire-clay 

Works,  Glasgow,  Scotland,  has  recently  perfected  an  improved 

£ 

FIG.  80. 


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300 


BRICK,  TILES   AND   TERRA-COTTA. 


regenerative  kiln  for  burning  fire-brick,  which  is  constructed 
upon  the  principles  just  described,  and  for  which  Charles  T. 
Davis,  of  Washington,  D.  C.,  is  the  agent  in  the  United  States. 
Figs.  80  to  88  represent  the  Dunnachie  kilns  arranged  in 
two  opposite  rows  or  series  of  five  each,  the  end  kiln  of  each 

FIG.  81. 


i 

1 

t 

FIG.  83. 


FIG.  84. 

series  being  connected  to  the  corresponding  end  kilns  of  the. 
other  series  by  means  of  flues. 

Fig.  80  is  a  general  plan  of  the  series  of  kilns.  Fig.  81  is  an 
end  elevation  of  the  same.  Fig.  82  is  a  front  elevation  of  one 
of  the  series  or  rows.  Fig.  83  is  a  longitudinal  vertical  section 
of  the  same.  Fig.  84  is  a  plan  of  the  same,  partly  in  section, 
on  the  line  I  2,  Fig.  83. 


KILNS. 


301 


The  following  figures  are  drawn  to  a  larger  scale,  the  beter 
to  exhibit  the  flues  and  passages :  Fig.  85  is  a  longitudinal  ver- 
tical section  of  a  kiln  of  the  series,  with  portions  of  the  adjacent 
kilns  on  either  side.  Fig.  86  shows  one-half  of  a  horizontal 
section  of  the  same,  taken  on  the  lines  3  4,  Fig.  85.  Fig.  87 
is  a  vertical  transverse  section  on  the  line  5  6,  Fig.  85,  show- 
ing the  side  wall  of  the  kiln,  indicated  by  the  arrow  7.  Fig.  88 
is  a  section  on  the  line  5  8,  Fig.  8 5,  but  showing  the  other  side 
wall  of  the  kiln,  as  indicated  by  the  arrow  9. 


FIG.  85. 


FIG.  87. 


FIG.  86. 


Fig.  88. 


The  gas  to  be  employed  for  the  burning  process  is  obtained 
from  any  convenient  source.  For  example,  it  is  produced  in  gas- 
producers,  indicated  at  A,  Fig.  80,  and  is  led  threfrom  by  the 
main  passage  a,  wherefrom  lead  branch  passages  a1  for  the  gas 
to  each  kiln,  a  valve  a2  being  upon  each  such  passage  to  regu- 
late the  supply  of  gas  to  each  kiln.  The  gas  passes  into  the 
kilns  by  openings  a3  and  a\  In  the  division  walls  which  sepa- 
rate the  kilns  are  duplex  hollow  spaces  or  flues  (marked  re- 
spectively B  and  C),  communicating  the  one  with  the  other  by 


3O2  BRICK,  TILES   AND   TERRA-COTTA. 

openings  £,  which  openings  are  regulated  or  closed  by  dampers 
c.  In  the  side  of  the  flue  C  are  passages  c1,  opening  from  the 
flue  just  above  the  outlets  for  gas  a*  in  the  one  kiln,  the  flue  B 
being  in  communication  by  the  slots  b\  passage  or  flue  <£3,  and 
slots  tf  with  the  lower  part  of  the  adjacent  flue.  A  duplex 
passage  consisting  of  flues  D  and  E  is  also  formed  in  the  upper 
part  of  the  walls  of  the  kilns,  the  one  passage  D  communicat- 
ing by  means  of  the  openings  d  with  the  one  kiln,  and  the  other 
passage  E  communicating  by  means  of  the  openings  e  with  the 
adjacent  kiln.  The  flues  D  and  E  communicate  with  each 
other  by  openings  </2,  which  can  be  regulated  by  dampers  <?2. 
Openings/  are  made  in  the  roofs  of  the  kilns,  which  openings 
are  covered  by  slabs  or  dampers  /2. 

In  operation,  when  one  kiln  is  in  fire  the  effluent  gases  pro- 
duced therein  are  passed  into  the  adjacent  kilns  through  the 
openings  d*,  passage  £3,  openings  d2,  passage  B,  openings  b,  and 
passage  C  into  the  adjacent  kiln  next  in  the  series  through  the 
openings  c*,  and  will  heat  the  contents  of  the  kiln.  When  the 
first  kiln  has  been  fired  off  the  air  passes  through  that  kiln  into 
the  adjacent  one  through  the  passages  B  and  C,  as  before  de- 
scribed, issuing  thereinto  by  the  openings  c2.  Gas  is  then 
turned  on  to  this  kiln,  and,  meeting  with  hot  air,  burns  and 
bakes  the  brick.  The  quantity  of  air  passing  through  the  one 
kiln  to  be  heated  on  its  passage  to  the  adjacent  one  is  regulated 
by  the  dampers  c,  and  the  quantity  of  gas  admitted  to  this  kiln 
is  regulated  by  the  valve  a.  When  this  last-mentioned  kiln  is 
burned  off,  the  supply  of  gas  is  turned  off  therefrom,  and  this 
one  becomes  in  its  turn  the  regenerator  or  heater  of  air  for  the 
next  kiln,  and  so  on  through  the  series,  the  passages  marked 
E1  and  C2  in  Fig.  80  giving  free  communication  between  the 
respective  end  kilns  of  each  row  of  kilns.  If  it  is  desired  to 
admit  hot  air  to  the  upper  part  of  any  kilns,  this  may  be  done 
by  opening  the  dampers  /2  at  the  top  of  a  fired-off  kiln,  and 
air  heated  by  the  kiln  thus  being  caused  to  pass  trom  the  kiln 
through  the  openings  d,  passage  D,  openings  d2,  and  passage 
E,  and  into  the  adjacent  kilns  through  the  openings  e  to  raise 


KILNS. 


303 


the  temperature  of  the  upper  part  of  the  kiln,  or  to  assist  in  the 
combustion  of  the  gas,  Where  cold  air  is  to  be  admitted,  air 
passes  through  the  flue  E,  which  is  open  to  the  atmosphere  at 
both  ends.  The  outlet-passages  from  each  kiln,  and  the  main 
flues  to  the  chimney  into  which  these  passages  open,  are  indi- 
cated in  Fig.  80,  and  are  there  marked  g. 

PERMANENT    KILN    ROOFS. 

By  having  the  roof  permanent,  a  great  saving  of  labor  in 
taking  off  and  putting  on  an  ordinary  wooden  roof  is  effected, 
and  the  waste  incident  to  the  repeated  handling  of  the  boards 
is  obviated.  It  renders  the  brickmaker  independent  of  the 

FIG.  89. 


weather,  as  his  kiln  is  covered  at  all  times,  and  the  doors  can 
be  shut  down  more  or  less  during  a  storm.  It  saves  fuel,  as  the 
heat  cannot  escape  so  rapidly,  and  the  proportion  of  hard- 
burned  brick  is  largely  increased,  and  a  much  greater  uniform- 
ity of  color  throughout  is  secured. 

The  kiln  roof  shown  in  Figs.  89,  90,  and  91  is  the  invention 


304 


BRICK,  TILES   AND   TERRA-COTTA. 


of  Mr.  Thos.  F.  Adams,  of  Philadelphia,  Pa.,  and  it  is  in  use  at 
the  works  of  the  Peerless  Brick  Company  in  that  city,  which 
company  controls  the  patent  right. 

The  roof  is  permanent  on  the  kiln,  and  enables  the  burner  to 
manage  the  direction  of  the  heat,  and  by  closing  and  opening 
the  doors  he  can  create  a  draft  at  any  part  of  the  kiln  he  may 
desire. 

Fig.  89  is  an  end  elevation  of  a  brick-kiln  embodying  this 
invention.  Fig.  90  is  the  transverse  vertical  section  of  the 
same.  Fig.  91  is  a  detail  view  of  a  part  thereof. 

FIG.  90. 


A  represents  the  ordinary  frame-work  of  a  brick-kiln,  which 
is  boarded  up  to  a  certain  height.  At  each  end  are  then  ap- 
plied sheets  B  By  of  iron,  to  complete  the  gable,  and  in  the 


KILNS.  305 

same  is  made  a  door  C,  which  is  hinged  at  its  upper  end,  and 
provided  with  a  chain  a,  passing  over  pulley  b,  at  the  top  of 
the  frame,  so  that  the  door  can  be  opened  more  or  less  from 
the  ground,  as  may  be  desired. 

To  the  frame-work  A  are  connected  suitable  upright  truss- 
frames  R  £,  standing  above  the  kiln  on  each  side,  and  to  these 
are  secured  rafters  D  D  on  each  side,  the  rafters  meeting  at 
the  top  in  the  centre,  and  sloping  downward  on  each  side  be- 
low the  truss-frames. 

The  roof  of  the  kiln  is  composed  of  iron  sheets  F  F,  which 
are  suspended  from  the  rafters  by  hooks  or  stirrups  d  d,  pass- 
ing through  the  sheets  and  fastening  in  rods  i,  running  from 
the  top  to  the  lower  edge  of  the  roof  on  each  side. 

At  the  top  in  the  roof  thus  formed,  are  made  hinged  doors 
G  G,  to  be  opened  more  or  less,  as  occasion  may  require. 

The  iron  roof  F  is  suspended  about  an  inch  below  the 
rafters,  so  as  to  prevent  any  liability  of  the  wood  catching  fire. 
20 


€=SE 
OF  THE 
LVERSITT 


CHAPTER  X. 

THE  MANUFACTURE  OF  FIRE-BRICK ;    SILICA  FIRE-BRICK ;    CAR- 
BON FIRE-BRICK  FOR  FURNACES  ;    GLASS  POTS  AND 
GAS  RETORTS. 

THE  essential  qualities  of  a  good  fire-brick  may  be  stated  as 
follows :  First,  infusibility ;  second,  regularity  of  shape  and  the 
power  to  retain  it  under  all  circumstances,  which  involves  per- 
fect uniformity  of  composition ;  third,  strength  to  resist  the 
different  pressures  required  under  different  circumstances; 
and  fourth,  its  cheap  price.  No  material  yet  manufactured 
fulfills  all  these  conditions ;  but  there  seems  to  be  no  reason 
why,  with  the  proper  investigation,  a  material  should  not  be 
made  which  will  fulfill  most  of  the  requirements  above  stated. 
No  brick  can  come  up  to  the  modern  standard  of  infusibility 
which  contains  5  per  cent  of  iron,  or  3  per  cent,  of  combined 
alkalies  or  alkaline  earths ;  and  yet  the  most  infusible  brick 
that  is  known,  which  in  the  roof  of  a  Siemens-Martin  furnace 
will  resist  250  charges,  and  then  wear  out  by  abrasion,  when 
required  to  come  in  contact  with  metals,  oxides  and  alkalies  in 
a  spiegel  cupola,  will  hardly  stand  25  heats,  although  an  iron- 
pipe  coil,  which  is  easily  destroyed  by  heat,  will  last  almost 
indefinitely  in  the  same  cupola,  provided  only  a  sufficient 
stream  of  water  is  run  through  it.  Different  furnaces,  and 
different  parts  of  the  same  furnace,  should,  therefore,  be  treated 
differently,  instead  of  being  treated  by  the  same  procrustean 
methods,  as  is  frequently  the  case.  If  silica  makes  the  best 
roof,  it  makes  the  worst  hearth.  Alumina,  when  present  in 
very  large  quantities,  even  in  the  presence  of  a  small  amount 
of  silica,  makes  compounds  which  are  almost  infusible,  so  that 
it  should  be  used  for  the  fire-bridges  and  hearths,  and  not  be 

(306) 


THE   MANUFACTURE   OF   FIRE-BRICK.  307 

put  into  the  roof,  where  its  tendency  to  contract  would  endan- 
ger the  structure  of  the  furnace. 

Far  too  little  attention  has  been  given  to  the  abrasive  and 
corrosive  power  of  coal-dust  and  ashes  carried  by  the  draft  in 
gradually  cutting  and  fluxing  away  the  parts  of  the  furnace  ex- 
posed to  its  action,  and  many  qualities  of  brick  which  are  in^ 
fusible  in  the  assay,  owe  their  small  power  of  resistance  to  its 
effect.  A  brick  to  be  used  where  it  is  to  be  exposed  to  such 
action  should  always  be  tested  by  placing  it  for  a  considerable 
time  on  the  bridge  of  the  furnace  where  it  is  to  be  used,  for  the 
destructive  effects  of  this  almost  unobserved  agency  seem  to 
be  greater  than  those  of  long-continued  heat. 

A  good  brick  should  not  only  resist  high  temperatures,  but 
sudden  changes  of  temperature,  without  alteration  of  any  kind, 
such  as  crushing,  splitting,  etc.,  and  at  a  high  temperature, 
should  undergo  the  least  possible  change  of  form.  In  general, 
it.  may  be  said  that  brick  which  have  undergone  a  very  high 
temperature  in  the  manufacture  are  less  liable  to  contract  after- 
ward. Shrinkage  is  generally  due  to  insufficient  burning,  or  to 
a  small  proportion  of  old  material  in  the  mixture,  and  gener- 
ally occurs  in  aluminous  brick.  Its  chief  evil  is  in  allowing  the 
flame  to  penetrate  the  open  joints  and  give  the  dust  an  oppor- 
tunity to  cut  between  the  brick,  for  any  cause  which  produces 
eddies  in  the  flames,  such  as  hollows  or  projecting  surfaces,  is 
certain  to  effect  the  destruction  of  that  part  of  the  furnace. 

Refractory  materials  may  be  classified  as  fire-stones  and  fire- 
clays. The  former  are  usually  silicious  rocks,  but  sometimes 
talcose  slates  or  soapstones  are  used,  which  stand  heat  well  in 
the  presence  of  basic  slags.  All  fire-stones  are  used  in,  the 
native  state,  with  no  other  preparation  than  the  necessary 
shaping.  Fire-clay  is  the  main  refractory  material,  and  is  used 
only  in  the  manufactured  state. 

Many  managers  of  rolling-mills  have  condemned  a  first-class 
fire-brick  because  the  crown,  or  roof,  of  the  puddling  furnace 
had  worn  in  an  irregular  manner,  holes  or  eddies  being  worn 
through  the  whole  depth  of  the  brick,  w.hile  the  brick  iri  the 


308  BRICK,  TILES   AND   TERRA-COTTA. 

same  roof  and  immediately  around  are  nearly  of  original  length. 
The  fire-brick  manufacturer  receives  the  complaint  and  is  sorry 
to  lose  his  customer  without  any  personal  investigation,  or 
probably  he  may  run  over  and  see  for  himself.  He  sees  an 
irregular  roof  with  holes  fused  through,  or  nearly  so,  and  the 
bulk  in  good  condition,  and  is  at  a  loss  to  explain  the  reason. 
He  may  be  satisfied  in  his  own  mind  that  the  brick  he  sent 
were  all  of  the  same  quality,  and  so  tell  the  manager.  This 
failure  may,  perhaps,  have  been  caused  by  some  No.  2  quality 
having  become  mixed  with  the  others  in  loading,  or  very  prob- 
ably, as  I  have  found  myself  under  such  circumstances,  that  the 
bricklayers  wanted  some  keys  or  wedges  to  get  the  proper 
radius,  and  have  been  obliged  to  take  a  make  of  brick  of  an- 
other manufacture  and  of  inferior  quality  from  the  stock-house. 
These  have  fused  more  readily,  as  they  have  worn  past  the 
other  brick,  forming  holes  or  eddies  in  which  the  flames  and 
dust  have  played,  thus  destroying  the  inferior  brick  much  more 
rapidly  than  if  the  whole  roof  had  been  built  with  them. 

A  practical  manufacturer  or  salesman,  who  understands  his 
business,  would  in  such  case,  go  over  and  investigate;  he  would 
take  pieces  of  the  longest  brick  least  damaged,  and  pieces  of 
the  small  ends  where  most  worn,  and  examine  the  fracture  of 
same ;  he  might  then  come  to  the  same  conclusion  as  we  have 
done  under  such  circumstances.  He  would  say  to  the  manager, 
"  Look  at  these  two  fractures ;  they  are  not  the  same  brick  or 
the  same  material ;  the  inferior  brick  is  some  other  manufac- 
ture." Then  take  the  pieces  into  the  stockhouse  and  compare. 
Thus,  in  place  of  losing  a  customer,  you  increase  the  popularity 
of  your  own  brick.  This  irregular  wearing  in  furnace  roofs  is 
very  important  to  the  mill  men,  as  it  is  necessary  that  the  roof 
be  perfectly  even  that  the  flame  may  have  a  clear  flow,  as  in 
case  of  its  obstruction  by  uneven  tops  or  eddies,  it  is  not  only 
destroying  the  fire-brick,  but  retarding  the  manufacture  of  the 
iron. 

Silicious  brick  have  a  tendency  to  expand  under  the  influence 
of  intense  heat.  This  is  true  to  such  an  extent  that  in  the  steel 


THE   MANUFACTURE-  OF   FIRE-BRICK.  309 

furnaces  where  they  are  used,  provision  must  be  made  for  slack- 
ening the  tie-rods  when  the  fire  is  being  raised,  and  tightening 
them  when  it  is  being  cooled. 

The  crushing  weight  of  an  ordinary  fire-brick  is  from  600  to 
1000  pounds,  but  some  of  the  best  have  been  known  to  resist 
as  high  as  3000  pounds  to  the  square  inch.  To  insure  the 
safety  of  the  structure,  and  the  success  of  the  process,  it  should 
not  only  retain  its  power  of  resistance,  but  should  not  undergo 
any  change  of  form  nor  soften  materially  under  long-continued 
heat,  and  at  the  highest  possible  temperature  should  support 
more  than  double  the  strain  required  without  alteration.  In  the 
walls  of  the  fire-place  those  brick  will  be  best  which  are  dense, 
and  contain  an  excess  of  silica.  In  the  hearth  they  should 
contain  an  excess  of  alumina.  In  the  arch  they  should  be 
nearly  pure  silica,  alumina  or  magnesia.  Brick  in  a  roof  give 
out  from  shrinkage,  cracking  or  splintering.  Splintering  may 
take  place  when  silicate  brick  are  made  of  impure  mixture,  but  it 
is  usually  caused  from  too  much  fine  material  and  from  imper- 
fect burning.  Brick  which  are  liable  to  splinter  are  generally 
cross-grained  and  dense,  with  a  smooth  conchoidal  fracture, 
when  made  from  improper  mixtures,  and  when  badly  burned 
they  generally  sound  like  a  cracked  vessel  when  they  are  struck 
together.  All  good  brick  wear  off  evenly. 

No  matter  how  good  a  material  may  be,  if  its  price  is  so 
high  as  to  prevent  healthful  competition,  it  might  as  well  not 
be  produced.  Hence  any  effort  to  furnish  a  good  material 
should  have  for  its  aim  to  make  it  at  the  least  possible  cost. 

In  discussing  the  manufacture  of  a  refractory  material  which 
is  to  be  used  in  a  given  locality,  there  is  to  be  taken  into  ac- 
count, first,  the  clay  and  other  materials  to  be  had ;  second, 
the  ore  or  metal  to  be  treated ;  third,  the  fuel  to  be  used ;  and 
fourth,  the  foreign  substances  in  the  gangue  of  the  ore  or 
metal.  Whether  to  use  a  given  clay,  or  a  mixture  of  calcined 
or  raw  clay,  must  be  determined  by  direct  experiment,  and 
then  the  size  of  the  grains  of  the  mixture  for  the  special  use 
must  be  determined,  for  each  substance  is  more  or  less  refrac- 


3IO  BRICK,  TILES    AND   TERRA-COTTA. 

tory  according  as  it  is  coarse  or  fine.  Thus,  in  Belgium  a 
porous  material  with  a  large  grain  is  used  for  blast-furnace 
brick,  but  a  fine  material  with  a  close  grain  for  coke-furnaces, 
the  chemical  composition  being  the  same  in  both  cases.  It  must 
then  be  ascertained  whether  the  mixture  contracts  or  expands, 
for  there  are  clays  that  contract  and  expand  between  one-thirty- 
second  and  one-eighth  of  their  bulk.  The  way  in  which  material 
tempers  must  then  be  carefully  studied.  It  is  not  sufficient  to 
have  a  good  material,  for  almost  as  much  depends  on  its 
manipulation  as  on  the  material  itself.  To  temper  properly, 
the  clay  and  the  manufactured  article  should  both  be  dried 
gradually  and  uniformly.  It  must  be  fired  evenly,  and  the 
temperature  slowly  raised  to  the  proper  point.  If  it  is  to  be 
used  in  the  raw  state  as  ganister,  it  must  be  equally  moist 
throughout,  so  as  to  dry  uniformly,  and  not  so  wet  as  to  cause 
it  to  crack  in  drying,  or  so  dry  as  to  prevent  its  binding.  The 
brick,  or  other  materials,  once  made,  should  be  kept  from 
dampness ;  as  they  are  porous,  and  likely  to  absorb  moisture, 
they  should  be  heated  before  being  used  in  the  furnace,  and 
put  in  as  hot  as  it  is  possible  to  handle  them.  If  the  furnace 
is  in  blast,  this  requires  a -special  furnace  and  a  high  heat.  .If 
it  is  to  be  put  in  blast  at  once,  especially  with  silica  brick,  the 
temperature  should  be  as  high  as  the  hand  can  bear.  If  the 
surface  is  to  be  a  long  time  standing,  this  precaution  is  not 
necessary,  but  in  the  last  two  cases  the  furnace  must  be  dried 
very  carefully  and  slowly.  No  brick  which  has  been  dressed 
should  ever  have  the  dressed  face  exposed  to  the  flame. 
Without  the  observation  of  these  precautions  a  really  good 
brick  may  give  a  very  bad  result.  It  is  too  much  the  habit  of 
$ris  age  to  be. in  a  hurry  to  get  results,  and  this  has  led  some 
folasb  furnace  managers  to  boast  that  steam  was  issuing  from 
the  top  of  their  furnace  while  cast-iron  was  being  tapped  from 
the  :bottom ;  but  under  such  management  we  never  hear  of 
long  campaigns,  but  very  frequently  hear  of  disasters. 
t:u:Iti'is  thus  seen  that  a  brick  which  is  good  for  the  cupola 
-would  be  worthless  for  the  reverberatory  furnace  ;  that  which 


THE    MANUFACTURE   OF   FIRE-BRICK.  311 

answers  well  for  iron  would  generally  be  worthless  for  zinc,  and 
a  crucible  which  is  excellent  for  steel  cannot  be  used  for  brass. 
It  is  not  the  way  to  realize  progress  to  keep  analyzing  natural 
substances  until  we  find  the  right  one,  or  make  repeated  trials 
and  depend  upon  them  alone.  All  investigations  go  to  show 
that  we  should  look  for  artificial,  and  not  for  natural  com- 
pounds ;  and  that  when  we  have  made  a  mixture  which  has 
stood  well,  we  are  then  to  analyze  and  examine  it  in  order  to 
reproduce  it.  Failure  in  this,  as  in  many  other  cases,  is  very 
often  owing  to  wrong  application  of  good  materials,  rather  than 
fault  in  the  materials  themselves. 

When  broken,  fire-brick  of  good  quality  should  show  a  com- 
pact and  uniformly  grained  structure,  free  from  cracks,  stones, 
etc.  When  struck,  they  should  emit  a  clear  and  ringing  sound. 
The  expansion  of  ordinary  fire-brick  by  heat  in  rising  from 
3*2°  F.  to  212°  F.  is  .00005,  according  to  Rankine.  All  fire- 
brick forming  the  lining  of  chimney-shafts  should  be  set  in 
ground  fire-clay  mixed  with  water  to  the  consistency  of  mor- 
tar. The  brick  are  sometimes,  before  being  laid,  dipped  into 
a  liquid  or  creamy  fire-clay,  and  when  laid  in  place  hammered 
together  so  as  to  be,  when  finished,  brick  and  brick.  This 
method  is  now  largely  adopted,  and  answers  admirably  where 
the  temperature  is  high. 

A  properly  burned  brick,  uniform  throughout  its  mass,  can 
be  obtained  only  by  very  slow  progressive  firing;  a  broken 
brick  which  has  been  too  quickly  burned,  though  pale  on  the 
surface,  presents  a  darker  central  patch  and  concentric  rings  of 
various  shades  of  color,  due  principally  to  the  different  states  of 
oxidation  of  the  iron,  and  partly  to  the  presence  of  unconsumed 
carbonaceous  matter. 

A  well-manufactured  fire-brick  should  be  of  a  pale  cream  or 
clear  buff  color,  uniform  throughout  its  mass,  and  burned  to 
the  full  extent  of  its  contractibility. 

The  chemical  changes  which  take  place  in  the  burning  con- 
sist, first,  of  the  destruction  of  the  disseminated  carbonaceous 
matter,  the  dehydration  of  the  silicates  of  alumina,  destroying 


312  BRICK,  TILES   AND   TERRA-COTTA. 

their  plastic  character,  and  the  decomposition  of  the  dissemi- 
nated carbonate  or  protoxide  of  iron,  converting  it  into  anhy- 
drous sesquioxide  to  which  the  yellow  of  the  burned  brick  is 
due. 

Should  the  burning  be  carried  to  a  very  high  state  of  vitrifi- 
cation the  yellow  tint  is  replaced  by  a  dull  gray,  due  to  the 
partial  reduction  of  the  sesquioxide  of  iron,  and  its  conversion 
into  silicate  of  protoxide  or  minutely  disseminated  particles  of 
metallic  iron.  Any  alkalies  also  present  form  vitreous  combin- 
ations with  the  silica  during  the  latter  stages  of  the  burning. 

But  the  paleness  of  Color  of  a  fire-brick  is  not  at  all  times  a 
safe  indication  of  the  absence  of  iron,  as  the  presence  of  a  large 
proportion  of  carbonaceous  matter  in  the  clay  tends  to  bleach- 
ing by  the  reduction  of  the  coloring  sesquioxide  to  lower  oxide 
preserved  as  a  silicate  in  a  comparatively  colorless  condition. 
Then,  again,  the  presence  of  lime  and  the  other  alkaline  earths, 
which  are  disadvantageous  fluxing  elements,  will  check  the 
coloring  power  of  a  large  percentage  of  oxide  of  iron  by  the 
formation  of  a  pale  double  silicate  of  lime  and  iron.  This  is 
largely  taken  advantage  of  in  the  manufacture  of  buff-colored 
building  brick,  and,  we  are  also  very  sorry  to  add,  in  the  pro- 
duction of  buff-colored  terra  cotta,  by  mixing  ground  chalk  with 
ferruginous  clays  which  would  otherwise  burn  a  dark  red  color. 

If  the  practical  manufacturer  wrants  a  brick  to  yield  slowly  to 
corrosive  influence,  a  simple  test  to  apply  is,  to  ascertain  the 
number  of  times  which  the  brick  can  be  melted  with  oxide  of 
lead  and  not  be  eaten  through.  In  fire-brick  constructions 
the  use  of  joints  of  clay  containing  free  silicic  acid  (quartz) 
should  be  avoided,  which  can  be  done  by  previously  saturating 
the  material  with  a  basic  burnt  clay. 

When  good  fire-brick  are  used,  it  is  important  that  clay 
equally  as  good  as  that  from  which  the  brick  are  made  should 
be  employed  in  which  to  lay  them.  When  ordering,  brick 
consumers  should  also  send  their  order  to  the  same  fire-brick 
manufacturer  from  whom  they  purchase  brick,  for  clay  of  the 
same  quality.  These  clays  are  usually  kept  in  stock,  and  fire- 


THE   MANUFACTURE -OF   FIRE-BRICK.  313 

brick  manufacturers  can  furnish  them  ground,  either  raw  or 
calcined,  in  bags  of  100  pounds  each,  or  in  barrels  or  in  bulk, 
as  may  be  desired.  From  6co  to  8co  pounds,  according  to  the 
way  the  clay  is  used,  is  sufficient  to  lay  one  thousand  nine-inch 
brick. 

It  is  recommended  that  No.  I  clay  be  used  with  No.  I  brick. 
The  brick  should  be  "dipped"  in  a  thick  "  soup  "  of  ground 
clay,  similar  in  character  to  that  from  which  the  brick  used  are 
made.  There  are  few  points  which  will  so  well  repay  con- 
sumers of  fire-brick  as  this  "  dipping"  will  do,  as  the  compara- 
tive first  cost  of  the  fire-clay  is  only  trifling. 

Fire-brick  Shapes. — The  wants  of  consumers  of  fire-brick  de- 
mand an  improved  form  in  presenting  the  lines  of  goods  carried 
by  manufacturers,  and  to  meet  this  demand  there  will  be  found 
illustrated  in  Figs.  92  to  101,  shapes  carried  in  stock  by  the 
well-known  firm  of  Messrs.  Fredericks,  Monroe  &  Co.,  Far- 
randsville,  Pa.,  from  whose  catalogue  the  illustrations  are 
selected. 

Refractory  Brick-Work  of  Blast- Furnaces,  and  its  Preserva- 
tion.*— Blast  furnaces  are  large  ga£  generators,  in  which  the 
gases  generated  reduce  the  iron  ore  and  carbonize  the  iron 
thus  produced,  whilst  the  heat  liberated  by  the  gasification  of 
the  carbon  melts  the  crude  iron  and  the  accompanying  con- 
stituents of  slag,  the  latter  being  presently  separated  from  the 
crude  iron.  In  these  few  words  is  expressed  the  diversity  of 
objects  the  blast-furnace  has  to  serve.  It  will,  however,  be 
seen  later  on,  that  besides  the  above-mentioned  processes, 
many  other  chemical  processes  take  place  in  the  blast-furnace. 
Moreover,  a  blast-furnace  has  to  be  worked  day  and  night  for 
many  years  in  succession,  so  that  there  is  but  little  opportunity 
for  thorough  repair  of  damages. 

On  the  other  hand,  a  kiln,  for  instance,  has  to  serve  but  one 
purpose,  and  hence  its  interior  can  every  few  days  be  thor- 
oughly inspected  and,  if  necessary,  repaired.  Moreover,  the 

*  Address  before  the  general  meeting  of  the  Association  of  German  Manufacturers 
of  Refractory  Materials,  in  Berlin,  February  24th.  1892.     By  Fritz  W.  Lfirmann. 


BRICK,  TILES   AND   TERRA-COTTA. 
FIG.  92. 


f)  (PICK   TO  THE   CIRO.L 


NINE-INCH   SHAPES. 


THE:  MANUFACTURE   OF   FIRE-BRICK. 
FIG.  93. 

"e'/t 


315 


M'KENZIE  CUPOLA  ^SHAPES. 


Diameter,  30  inches  inside,  39  inches  outside. 


CUPOLA   BLOCKS. 


316  BRICK,  TILES   AND   TERRA-COTTA. 

arrangement  and  producing  capacity  of  the  blast-furnace  have 
for  the  last  forty  years  been  constantly  changed.  The  first 
coke  blast-furnace  in  Westphalia  was  built  forty  three  years 
ago,  but  the  size  and  arrangements  of  those  blast-furnaces  can- 
not be  compared  with  the  present  ones. 

A  daily  out  put  of  40,000  pounds  of  pig-iron  was  at  that 
time  considered  something  enormous,  whilst  the  present  blast- 
furnaces of  the  different  German  iron  districts  produce  on  an 
average  ten  times  that  quantity. 

The  various  purposes  which  a  blast-furnace  has  to  serve,  the 
many  chemical  processes  which  take  place  in  it,  and  the  long- 
continued  and  enormously  increased  work  expected  from  it, 
will  sufficiently  explain  the  difficulties  of  procuring  a  refractory 

material  for  the  brick-work  which  will  answer  all  demands.     In 

• 

regard  to  blast-furnaces,  the  term  "  refractory,"  as  generally 
applied  to  brick,  means  a  great  deal  more.  The  exposure  of  a 
so-called  refractory  material  to  the  action  of  heat  alone  is  some- 
thing entirely  different  from  its  being  at  the  same  time  exposed 
to  various  other  influences.  Now,  in  the  blast-furnace,  besides 
heat,  slag  and  other  hot  liquid  and  gaseous  combinations,  sim- 
ultaneously exert  a  dissolving  influence  upon  the  refractory 
material. 

Thanks  to  the  constant  improvement  in  the  manufacture  of 
refractory  material,  there  is  no  difficulty  in  procuring  brick 
capable  of  resisting  the  highest  degree  of  heat  at  present  at- 
tainable. But  as  regards  resistance  against  the  dissolving  in- 
fluences upon  the  brick-work  of  the  blast-furnace,  there  is  no 
material  known  at  the  present  time  which  can  successfully  with- 
stand these  influences. 

Quartz,  as  well  as  the  best  refractory  brick,  withstands  the 
dissolving  action  of  slag,  etc.,  as  little  as  ordinary  brick,  because 
the  principal  constituents — silica  and  alumina — of  all  these 
materials  are  with  avidity  dissolved  by  the  slag,  no  matter  in 
what  proportions  to  one  another  they  may  occur  in  them.  The 
dissolution  may  be  slightly  retarded  if  the  brick  possesses  great 
density — hence  mechanical  strength — without  brittleness.  But 


THE   MANUFACTURE   OF   FIRE-BRICK. 


317 


dense  or  loose,  all  so-called  refractory   brick  are   finally  dis- 
solved, just  as  sure  as  sugar  is  in  coffee. 

FIG.  94. 


16  in. 


\ 

Win.,                          \ 

—  4 

V             \ 

Straight                                                \ 

10  ft.          §                                    / 
Circle.                                           / 

16  lnches.10  ft.Boe 


10  tachea-a  ft. Bosh 


BLAST-FURNACE   BOSH. 


BLAST-FURNACE    LININGS. 


318 


BRICK,  TILES   AND   TERRA-COTTA. 


That  a  material  need  not  be  refractory  according  to  the  or- 
dinary understanding  of  the  term  in  order  to  resist  the  dissolv- 
ing action  of  the  slag,  etc.,  is  proved  by  the  use  of  carbon  brick. 


Circle 


4V4 


FIG.  95. 


13%-INCH   BLAST-FVRNACE  LINING   BRICK. 

They  are  made  2^  inches  thick,  so  as 
to  be  used  in  the  same  coursfe  with  9  inch 
square  and  key  brick,  in  making  13% 
inch  linings.  ,  < 


13* 


Straight 


13V4 


3  X  Inch  No.  2  Key. 

M    FT.OlAMETtR. 

TO  THC  C'RCLt 


BLAST-FURNACE  LININGS. 


BLAST-FURNACE  3OTTCJMS. 


THE   MANUFACTURE    OF    FIRE-BRICK. 

The  best  means  of  preserving  the  walls  of  blast-furnaces 
without  regard  to  the  material  used  in  their  construction  is  to 
cool  them  with  water. 

The  carbon  brick,  which  have  now  been  largely  introduced, 
have,  since  1876,  been  used  in  France  for  constructing  the 
walls  of  the  hearths  of  blast-furnaces,  and  at  first  appeared  to 
be  very  suitable  for  that  purpose. 

These  carbon  brick  are  not  dissolved  by  the  slag,  and  if  the 
latter  alone  were  present  in  the  hearth  of  a  blast-furnace,  they 
would  prove  to  be  of  great  durability. 

However,  in  the  hearth,  and  always  upon  the  bottom  Of  it,  is 
also  the  crude  iron.  Now,  in  the  blast-furnace,  iron 'is  pro- 
duced which  is  not  yet  saturated  with  carbon,  and,  therefore, 
absorbs  the  latter  with  avidity  when  it  comes  in  contact  with 
coke,  and,  hence,  also  when  in  contact  with  the  carbon-brick. 

By  the  solution  of  their  carbon,  these  carbon-brick  are,  of 
course,  destroyed,  and  this  is  the  reason  that  many  bottoms  of 
blast-furnaces,  as  well  as  the  lower  portions  of  the  hearth,  con- 
structed of  carbon-brick,  are  rapidly  dissolved.  Hearth- bottoms 
constructed  of  carbon-brick  have  shown  the  least  durability, 
whilst  the  same  material,  when  used  for  the  portions  of  the  walls 
of  the  hearth  and  of  the  boshes  which  do  not  constantly  come 
in  contact  with  the  liquid  iron,  is  apparently  quite  durable. 
However,  since  carbon-brick  have  been  in  general  use  for  a 
short  time  only,  experiences  in  regard  to  the  latter  subject  are 
not  sufficient  to  allow  of  a  final  judgment.  Formerly,  when 
blast-furnaces  were  worked  more  slowly,  only  the  refractory 
brick-work  of  the  hearth  was  dissolved,  but  in  consequence  of 
the  constantly  increasing  demands  made  on  the  blast-furnaces 
by  working  with  the  introduction  of  more  and  hotter  blast,  the 
dissolution  first  extended  to  the  boshes  and  lately  even  to  the 
refractory  brick-work  of  the  stack. 

Cooling  with  water  being  the  only  means  known  at  present 
for  preserving  the  brick-work  of  blast-furnaces,  not  only  the 
hearth,  but  also  the  boshes,  and  in  recent  times,  the  stack  as 
well  are  cooled. 


32° 


BRICK,  TILES   AND   TERRA-COTTA. 

• 

FIG.  96. 


SIEMENS  CRUCIBLE  STEEL  MELTING  FURNACE. 

List  of  Shapes  required  for  one  6-pot  furnace. 

No.  AA    4  pieces. 

No.  A 26      « 

No.B 18      « 

No.  C 16      " 

No.  3 12      " 

No.  4 2      " 

No.  5 2      " 

No.  6 2      « 


\ 


SIEMENS   HEATING   FURNACE  BLOCKS. 


THE   MANUFACTURE,  OF   FIRE-BRICK.  321 

It  is  not  necessary  to  discuss  here  the  cause  of  the  great  wear 
of  certain  portions  of  the  stack  of  a  blast-furnace  in  which 
ferro-manganese  is  produced,  the  production  of  the  latter  being 
a  limited  one.  As  causes  of  the  rapid  wear  of  the  brick-work 
of  the  stacks  of  blast-furnaces  in  general,  from  a  height  of  sev- 
eral meters  to  a  few  millimeters  towards  the  exterior,  must  be 
mentioned : 

1 .  Abrasion  by  the  downward  passage  of  the  charge. 

2.  The  action  of  constituents  of  blast-furnace  gases,  for  in- 
stance, cyanogen  and  its  salts. 

3.  Melting  off  by  common  salt,  which  is  contained  in  coke. 

4.  Cracking   by    separations    of    carbon   and  carbonic   acid 
caused  by  iron  particles  which  are  formed  from  iron  disulphide 
(FeS2)  in  the  refractory  brick. 

Of  the  above-mentioned  causes,  either  one  or  all  may  act 
upon  the  brick  of  the  stack  of  a  blast-furnace. 

Ad.  i.  With  the  present  improvements,  it  is  not  difficult  to 
produce  refractory  brick  which  will  resist  abrasion  by  the  down- 
ward passage  of  the  charge.  Hence,  this  cause  need  only  in 
exceptional  cases  be  taken  into  consideration  for  explaining 
the  rapid  wear  of  the  brick-work  of  blast-furnace  stacks. 

Ad.  2.  It  is  a  well-known  fact  that  blast-furnace  gases  contain 
much  cyanogen.  The  formation  of  it  in  the  blast-furnace  is 
much  faciliated  by  the  occurrence  of  nitrogen  together  with 
carbon  in  coke.  By  coking  Westphalia  coals  in  coke-ovens  or 
gas-retorts,  31  to  36  per  cent,  of  their  nitrogen  remains,  accord- 
ing to  Dr.  Knoblauch,  in  the  coke;  1.5  to  2  per  cent,  of  the 
nitrogen  passes  over  as  cyanogen,  whilst  I  to  3  per  cent,  of  it 
is  found  in  the  tar,  and  10  to  14  per  cent,  of  it  in  the  ammonia. 

One  cubic  meter  (1.308  cubic  yards)  of  the  top-gas  of  a 
modern  blast-furnace  contained  1.97  to  6.6  grammes  (30.4  to 
101.85  grains)  of  cyanogen,  whilst  the  gases  from  the  melting- 
zone  were  still  richer  in  it.*  One  ton  of  coke  yielding  about 
4733  cubic  meters  of  gas,  the  amount  of  cyanogen  produced 

*  These  analyses  were  made  in  the  laboratory  of  the  Clarence  Iron  Works,  Middles- 
borough,  England. 
21 


322 


BRICK,  TILES   AND   TERRA-COTTA. 


from  it  in  the  blast-Iurnace  would  be  from  8.48  to  31.23  kilo- 
grammes (18.65  to  68.7  Ibs.).  Hence  a  blast-furnace  with  a 
daily  consumption  of  but  100  tons  of  coke  would  produce  848 
to  3.123  kilogrammes  (1865.6  to  6870.6  Ibs.)  of  cyanogen. 

FIG.  97. 


20 


SIEMENS  REGENERATOR  TILE  AND  BRICK. 


The  following  sizes  are  kept  in  stock : 
16x6x3.  22  x  6  x  3. 

18x6x3.  24  x  6  x  3. 

19  x  6  x  3.  24  x  9  x  3. 

20  x  6  x  3.  26  x  9  x  3. 
21x6x3. 

All  other  sizes  are  usually  made  to  order. 


It  is  customary  in  large  works  to 
keep  an  ample  stock  of  checker 
brick  always  on  hand  to  meet  all 
orders. 


All  sizes  are  usually  made  to  order. 


All  sizes  are  usually  made  to  order. 


GUuu  Poo  Stopper. 

All  sizes  and  styles  are  usually  made  to  order. 

GLASS-FURNACE  BRICK. 

These    immense,    and    therefore    improbable,    quantities    of 
cyanagon,  in  connection  with  alkalies  or  alkaline  earths,  and 


THE   MANUFACTURE  -  OF   FIRE-BRICK. 


323 


perhaps  also  with  volatile  metals,  would  suffice  to  explain  the 
rapid  wear  of  all  parts  of  the  refractory  brick  above  the  melt- 
ing zone  of  the  blast  furnace.  In  the  refractory  clays,  which 
are  products  of  the  decomposition  of  feldspathic  minerals,  alka- 
lies generally  occur. 

Whether  the  cyanogen  in  the  blast-furnace  gases  is  capable 

FIG.  98. 


36 


33 


LOCOMOTIVE  FIRE-BOX  ARCHES. 


of  withdrawing,  at  the  temperatures  prevailing  in  the  stack  of  a 
blast  furnace,  alkalies  from  the  refractory  brick,  and  thus  to 
decompose  them,  would  have  to  be  determined  by  experiments. 
It  is,  however,  an  established  fact  that  parts  of  the  cast  iron  of 
the  apparatus  for  collecting  the  waste  gases  as  well  as  of  the  iron 


324  BRICK,  TILES   AND   TERRA-COTTA. 

used  as  a  support  of  the  top  of  the  furnace  are  frequently  com- 
pletely corroded  by  the  constituents  of  the  blast-furnace  gases. 

It  has  not  yet  been  determined  whether  cyanogen  in  the 
blast-furnace  gases  is  capable  of  withdrawing  alkalies  and  earths 
from  the  materials  of  the  charge,  and  in  the  form  of  cyanide 
of  potash  or  volatile  cyanide  exerting  a  destructive  effect  upon 
the  refractory  brick.  Large  quantities  of  cyanide  of  potash  are 
dissolved  from  the  walls  of  blast-furnaces  by  the  cooling  water, 
and  fused  salts  of  cyanogen  also  drip  frequently  from  the  joints 
of  the  walls. 

Ad.  j.  As  is  well-known,  the  coal-measures  contain  springs 
strongly  impregnated  with  common  salt,  and  hence  the  latter 
is  frequently  found  also  in  the  coal.  According  to  experiments 
made  in  1884,  a  charge  of  6,000  kilogrammes  (13,200  Ibs.)  of 
coal  of  a  coke-oven  contained  1.8  kilogrammes  (3.96  Ibs.)  of 
common  salt ;  another  charge  of  the  same  quantity  of  coal,  3 
kilogrames  (6.6  Ibs.),  and  one  as  much  as  22  kilogrammes 
(48.4  Ibs.).  Common  salt  is  volatile;  it  partially  evaporates  in 
coking  the  coal,  and  in  coke  ovens,  worked  without  gaining  the 
by-products,  it,  together  with  the  hot  products  of  combustion 
of  the  gases — hence  at  a  white  heat — comes  in  contact  with  the 
hot  refractory  brick,  and,  by  the  silica  of  the  latter,  is  decom- 
posed to  sodium  and  chlorine. 

The  sodium  combines  with  the  silica  and  alumina  of  the  re- 
fractory brick  to  a  liquid  slag,  which  drops  off.  In  conse- 
quence of  the  development  of  chlorine  the  brick  acquires  a 
spongy  appearance.  An  analysis  of  such  brick  showed  a  con- 
tent of  7.17  per  cent,  of  sodium.  The  brick  of  the  walls  of 
such  coke  ovens  are  completely  dissolved  by  this  action. 
Large  quantities  of  free  chlorine  are  contained  in  the  gases  of 
coke-ovens. 

This  destruction  of  coke-ovens  has  caused  many  losses. 
With  coke-ovens,  where  the  by-products  are  gained,  the  con- 
tent of  salt  in  the  gases  is  not  injurious.  However,  a  portion 
of  the  salt  remains  in  the  coke,  and  according  to  recent  experi- 
ments, the  different  cokes  used  in  the  blast-furnaces  of  a  large 


THE   MANUFACTURE   OF   FIRE-BRICK. 


325 


concern  contained,  on  an  average,  0.181  per  cent,  of  salts  solu- 
ble in  water,  namely:  0.062  per  cent,  of  sodium  sulphate  (Na2- 


Crown  Brick 


S&                           "     S 

* 

e          „, 

12 


FIG.  99. 


10 


\ 


\ 


18 


Sizes  kept  on  hand:  18x12x2,  12x12x2,  18x12x3, 
12x16x3,  16x20x3. 


COKE-OVEN  BRICK  AND  TILE. 


Feed-Holes  for  use  in  Saw-Mills  and  Tanneries: 
12  and  16  inch  hole  kept  in  stock. 

FEED-HOLE  BLOCKS. 


326  BRICK,  TILES   AND   TERRA-COTTA. 

SO4),  and  O.I  19  per  cent,  of  common  salt  (NaCl).  According 
to  this,  62  kilogrammes  (136.4103.)  of  sodium  sulphate,  and 
119  kilogrammes  (261.8  Ibs.)  of  common  salt  are  introduced 
into  a  furnace  consuming  only  100  tons  of  coke  per  day.  As 
is  well  known,  common  salt  is  used  for  glazing  vessels  of  clay 
and  stoneware. 

If  now  the  refractory  brick  of  the  walls  of  blast-furnaces  are 
constantly  exposed  to  the  action  of  such  large  quantities  of 
salt,  and  hence  become  glazed,  they  will  just  as  well  wear  out 
in  a  few  months  as  those  of  the  coke-ovens. 

Ad.  4..  In  most  beds  of  the  best  refractory  clays  occur  pyrites 
which,  at  higher  temperatures,  are  converted  into  ferrous  sul- 
phide ;  the  latter  by  the  gases  of  the  blast-furnace  is  converted 
into  metallic  iron. 

With  this  metallic  iron  the  gases  of  the  furnace,  in  which 
large  quantities  of  carbonic  oxide  occur,  remain  in  further  con- 
tact. By  the  contact  with  the  metallic  iron  the  carbonic  oxide 
is  decomposed  to  carbon  and  carbonic  acid,  the  carbon  de- 
positing upon  the  surface  of  the  small  iron  balls  and  forming  a 
shell  around  them.  Notwithstanding  this  shell  of  carbon,  new 
carbonic  oxide  gases  constantly  penetrate  to  the  iron,  fresh 
carbon  being  always  deposited  upon  the  latter. 

The  very  minute  balls  of  iron  are  thus  gradually  surrounded 
with  an  envelope  of  carbon  the  size  of  a  pea  and  a  hazel-nut. 
Nothing,  and  least  of  all  the  refractory  brick  of  the  furnace, 
can  withstand  this  gradually  augmenting  separation  of  carbon ; 
the  brick  being  thereby  cracked  and  completely  destroyed. 

The  brick-work  of  blast-furnaces,  if  constructed  of  carbon 
brick,  would  not  be  exposed  to  the  three  last-mentioned 
causes  of  destruction.  Carbon  brick  are  now  made  without  the 
addition  of  clay,  etc.  They  possess  a  considerable  degree  of 
hardness  and  solidity,  so  that  they  would  oppose  considerable 
resistance  to  abrasion  by  the  downward  passage  of  the  charge. 
They  may  also  be  used  not  only  for  the  boshes  but  also  for  the 
stack. 

Carbon  Deposits  in  Fire  Brick.     (Written  for  the  Engineer- 


THE   MANUFACTURE   OF   FIRE-BRICK. 


327 


ing  and  Mining  Journal  by  A.  D.  Elbers.)  The  following 
extract  from  a  recent  essay  on  "  The  causes  of  the  destruction 
of  fire-brick  in  blast-furnace  linings,"  Stahl  und  Eisen,  March 
1 5th,  1892)  is  noteworthy: 

Cause  No.  4. — Bursting,  from  the  formation  of  carbon  de 

FIG.  100. 


25 


4 '/a 


Velvetrv  Tilt 


18 


Stock  Hole  TUe, 


Bridge    Block. 
ROLLING-MILL  TILES. 


posits,    within    the    brick,  on  particles   of    iron  derived  from 
pyrites. 


328  BRICK,  TILES   AND   TERRA-COTTA. 

This  hypothesis — analogous  to  that  of  lumps  of  ore  bursting 
in  the  blast  furnace  by  reason  of  their  impregnation  with  de- 
posited carbon — is  accounted  for  as  follows :  "  The  ferric  disul- 
phide  (pyrites)  changes  at  elevated  temperatures  to  ferrous 
sulphide,  the  latter  is  changed  by  the  blast-furnace  gases  to 
to  -metallic  iron,  and  on  this  iron  the  carbonic  oxide  gas,  in 
permeating  the  brick,  deposits  carbon  according  to  the  reaction  : 
2CO  =  CO2  4-  C.  The  particles  of  iron,  which  are  quite  dimin- 
utive, thus  become  coated  with  carbon,  and  this  deposition 
continues  until  the  coated  particles  grow  to  lentil,  pea,  or  even 
to  hazel-nut  size,  and  then — burst  the  brick !" 

The  assumed  but  undefined  reaction  by  which  the  gas-fur- 
nace gases  are  supposed  to  "  change"  ferrous  sulphide  to  me- 
tallic iron,  serves,  in  this  instance,  to  support  an  apparently 
fallacious  theory ;  for  at  the  temperature  at  which  FeS  or  Fe7S8 
can  lose  the  remainder  of  their  sulphur,  no  deposition  of  car- 
bon takes  place.  In  other  words,  if  the  brick  in  any  particular 
spot  of  the  furnace  is  hot  enough  to  render  the  complete  oxida- 
tion of  the  sulphur  possible,  then  that  brick  is  too  hot  for  the 
carbonic  oxide  gas  that  enters  its  interstices  to  split  up  into 
carbonic  acid  gas  and  solid  carbon. 

Nevertheless,  deposits  of  the  latter  do  form  in  the  brick  lin- 
ings of  blast-furnaces,  where  the  brick  is  not  too  hot.  These 
formations  must,  however,  not  be  ascribed  to  the  presence  of 
converted  pyrites,  but  to  particles  of  iron  derived  from  the  ferric 
hydrate  obtained  in  the  clay,  or,  also,  to  chips  from  the  crusher 
in  which  the  clay  was  ground.  That  the  accumulations  of  car- 
bon on  these  particles  cannot  increase  to  the  extent  of  exerting 
a  "breaking"  strain  on  the  brick  in  which  they  are  lodged  is 
almost  self-evident,  because  the  pressure  which  they  exert 
within  the  brick  cannot  be  greater  than  that  of  the  air  or  gases 
inside  the  furnace,  and  also  because  the  deposited  carbon  is  of 
no  greater  density  than  the  brick  components  are.  Nor  is 
there  such  a  difference  in  the  coefficients  of  expansion  of  im- 
pregnated carbon  and  brick  substance  as  to  render  it  possible 
that  the  carbon  should  expand  at  an  increased  temperature 


THE   MANUFACTURE   OF   FIRE-BRICK. 


329 


sufficient  to  burst  the  brick,  or  that  the  brick  should  break 
at  a  lower  temperature  on  account  of  the  unequal  contraction 
of  the  respective  substances. 

But  what  can  happen  very  frequently  is,  fire-brick  bursting 


A 


FIG.  101. 


20 


/ 

/ 

1  1 

i     IF 

Corrugated. 
TILE  FOR  FIRE-PLACES. 


330  BRICK,  TILES   AND    TERRA-COTTA. 

on  account  of  the  sudden  expansion  of  its  free  silica  at  high 
heat.  Cracks  may  then  open  in  the  brick  wide  enough  to  let 
even  carbon  lumps  of  hazel  nut  size  drop  into  them  from  the 
descending  burden  ;  and  when,  at  a  receding  temperature,  these 
cracks  become  partly  closed,  then  the  carbon  lumps  that  have 
dropped  in  will  be  held  so  tightly  as  to  give  rise  to  the  suppo- 
sition that  the  brick  had  been  ruptured  by  their  expansion. 
This  belief  is  apt  to  be  strengthened  when  other  (but  smaller) 
aggregations  of  carbon  are  found  to  obtain  in  unfractured  parts 
of  the  same  brick,  into  which  they  could  not  have  dropped 
from  without. 

The  conditions  for  the  complete  desulpurization  of  contained 
pyrites  obtain  sometimes  in  the  fire-brick  kiln,  but  not  in  the 
blast-furnace  lining;  and  the  blast-furnace  brick  may  contain 
impregnated  carbon  that  has  been  formed  within,  as  well  as 
carbon  that  has  dropped  in,  but  neither  is  likely  to  cause  the 
rupture  of  the  brick. 

Fire-Brick.  Special  Shapes. — A  large  proportion  of  the  work 
done  by  the  leading  fire-brick  manufacturers  is  on  special 
orders  for  all  kinds  of  irregular  and  difficult  work.  To  endeavor 
to  fully  illustrate  this  department  of  fire-brick  manufacture 
would  be  impracticable  as  well  as  useless.  In  order,  however, 
that  the  reader  may  have  a  good  idea  of  the  leading  specialties 
in  the  different  departments,  ordinarily  kept  in  stock,  we  have 
drawn  on  the  catalogue  of  the  well  known  firm  of  Harbison  & 
Walker  Co.,  of  Pittsburgh,  Pa.,  for  the  illustrations  shown  in 
Figs.  102  to  125.  It  is  of  great  importance  in  ordering  refrac- 
tory materials  of  any  character  to  state  explicitly  the  nature  of 
the  service  required  of  the  ware,  when  the  orders  are  given,  so 
that  the  manufacturer  can  fill  them  with  the  stock  best  suited 
for  the  purpose. 

Sorting  Fire-Brick — There  are  three  grades  of  fire-brick 
which  can  be  recognized.  The  first  or  No.  I  is  the  best  and 
most  refractory,  and  is  intended  for  the  severest  use,  such  as 
the  hearth  and  boshes  of  the  blast-furnace,  the  exposed  parts 
of  puddling-furnaces  and  steel-mill  plants.  Its  application  en- 


THE   MANUFACTURE    OF   FIRE-BRICK. 
FIG.  102. 


331 


PLAN   OF    SIEMENS    STEEL   FURNACE. 


.(UNIVERSITY 


332  BRICK,  TILES   AND   TERRA-COTTA. 

forces  the  use  of  a  very  large  proportion  of  calcined  and  flint 
clays  with  the  least  possible  plastic  clay  which  will  bind  them 
together.  In  several  places  the  mixture  is  composed  of  about 
half  and  half  of  each  of  these,  with  no  plastic,  and  the  mixture 
is  ground  very  severely  in  a  heavy  wet-mill  for  a  long  time. 
The  more  usual  charge  for  a  No.  I  brick  consists  of  about  45 
per  cent,  of  both  flint  and  calcine  and  10  per  cent,  plastic. 

The  cohesion  among  the  particles  of  such  a  mixture  is  very 
slight,  and  very  light  friction  suffices  to  shell  the  brick  up  into 
its  component  parts ;  it  is  of  course  unfitted  for  use  in  any 
position  where  friction  will  be  brought  to  bear,  but  at  the  in- 
tense heat  at  which  they  are  used,  the  softening  of  the  clay 
makes  them  as  cohesive  as  need  be,  and  in  that  state  the  fric- 
tion of  matter  as  highly  heated  as  the  brick  has  but  little  effect. 

The  next  well-marked  grade  of  brick  has  neither  name  nor 
number  among  its  makers.  It  is  composed  of  about  equal 
amounts  of  both  flint  and  calcine,  and  about  three  times  as 
much  plastic  as  the  No.  I  brick. 

Its  proper  uses  are  the  same  general  kind  as  those  for  the 
No.  i  brick,  but  the  product  is  a  little  inferior  to  it.  The  next 
grade,  or  No.  2  brick,  is  made  of  about  50  per  cent,  of  plastic, 
20  per  cent,  calcine  and  30  per  cent,  flinty  clay;  it  has  a 
homogeneous  appearance  on  its  fracture,  is  close-grained,  and 
emits  a  sharp  ring  when  struck  with  another  brick.  Such  a 
brick  will  sometimes  stand  a  very  fair  heat  with  no  symptoms 
of  fusing,  but  as  a  rule  it  is  not  fitted  for  any  responsible  posi- 
tion. It  is  excellent  material  from  which  to  make  kilns,  etc., 
except  the  hottest  parts.  What  might  be  denominated  a  No.  3 
brick  consists  of  a  mixture  of  several  plastic  clays,  or  else  a 
body  made  of  one  plastic  grade.  They  are  generally  vitrified 
slightly  in  the  burning  heat  of  a  kiln,  and  precaution  must  be 
taken  to  keep  them  from  sticking  together.  They  are  excellent 
for  making  flues,  pavements,  boiler-settings,  chimneys,  etc.,  and 
as  they  can  be  well  made  by  a  machine  they  ought  to  be  fur- 
nished at  low  rates.  The  burning  of  these  various  grades  of 
brick  demands  considerable  technical  skill.  The  products  ex- 


THE   MANUFACTURE  'OF   FIRE-BRICK. 


333 


hibit  many  phenomena  which  are  very  interesting;  iron,  in 
particular,  is  noticed  in  the  black  blotches  which  its  union  with 
silica  has  caused. 

FIG.  103. 


SIEMENS  REGENERATOR  BLOCKS. 
FIG.  104. 


-3 

N?3I 
13 

IB 

SKEW  FOR  FURNACE  ROOF. 


WEDGE  FOR  FURNACE  ROOF. 

SIEMENS   HEATING   FURNACE  BLOCKS. 


334 


BRICK,  TILES   AND   TERRA-COTTA. 
FIG.  105. 


ARCH   TILE   FOR   DOOR   OF   FURNACE. 

FIG.  106.  FIG.  107. 


SWINDELL'S  PATENT  CHECKER.  MCKENNA'S  PATENT  CHECKER. 

FIG.  1 08. 


BESSEMER   CONVERTER  TUYERE. 

The  following  sizes  of  tuyeres  are  made : 

Length  of  tuyere,  "  21  inch,"  "  22%  inch,"  "  24  inch." 

Diameter  of  tuyere,  7  inch  large  and  5^  inch  at  shoulder,  5%  inch  small  end. 

Size  of  hole,  %  to  %  inch  each. 

Number  of  holes,  7  to  12  in  each  tuyere. 


FIG.  109. 


FIG.  no. 


FIG.  in. 


8  INCH  SLEEVE,  FOR 
STOPPER  ROD. 


4  INCH  SLEEVE,  FOR 
STOPPER  ROD. 


4  INCH  LADLE 
NOZZLE. 


The  following  sizes  of  laddie  nozzles  are  made: 
4  inches  long,  with  i%  inch  hole  for  bottom  casting. 
4  inches  long,  with  i%  inch  hole  for  bottom  casting. 
4  inches  long,  with  i%  inch  hole  for  bottom  casting. 
4  inches  long,  with  i  %  inch  hole  for  bottom  casting. 
4  inches  long,  with  2%  inch  hole  for  top  casting. 


THE   MANUFACTURE   OF   FIRE-BRICK. 


335 


Often  a  nail,  bolt,  or  some  stray  piece  of  iron  gets  into  a  kiln 
of  brick.  Its  effects  can  be  seen  in  a  large  conical  hole  in  the 
brick,  lined  with  the  black  cinder  of  iron,  and  extending  down- 


SECTJON    OF   IRON    CUPOLA. 


336 


BRICK,  TILES    AND   TERRA-COTTA. 


ward  as  far  as  the  iron  lasted.  The  blackening  of  the  faces  of 
the  arch  brick  and  those  most  exposed  to  the  direct  heat  of  the 
fires  has  often  been  mentioned  by  brick  men  as  being  the  re- 
sult of  impure  fuel  and  sulphur  in  the  coal.  This  explanation 
is  incorrect;  sulphur,  i.  e.,  sulphide  of  iron,  when  burned  in  a 
grate  would  decompose  to  SO2  or  sulphurous  anhydride,  and 
in  that  state  would  pass  into  the  kiln.  The  only  effect  the  gas 
could  possibly  have  on  hot  silicate  of  alumina  or  any*body 
likely  to  be  present  in  clay,  would  be  to  recombine  in  the  same 
state  from  which  it  has  just  been  expelled  by  a  less  heat  than 
is  met  in  the  inside  of  a  kiln.  The  true  explanation  is  this : 
the  heat  on  the  brick  that  are  blackened  is  more  intense  than 
on  any  other  part  of  the  kiln,  and  they  are  rendered  softer  and 
nearer  to  fusion ;  while  in  this  pliable  state  the  draft  from  the 
fires  just  outside  carries  in  a  very  appreciable  amount  of  dust 
and  ashes,  which  lodge  on  these  portions  and  flux  outside  to 
the  black  crust  seen. 

Blocks,  Tiles  and  Special  Pieces,  and  their  Manufacture. — In 
addition  to  the  manufacture  of  fire-brick  the  same  establish- 
ment usually  produces  many  other  kinds  of  wares,  notably, 
blast-furnace  linings  and  special  pieces. 

FIG.  113. 


SPIEGEL   CUPOLA  BRICK.  SIX   INCH   CUPOLA   BRICK. 

All  sizes  made  to  order. 
For  sizes  kept  in  stock. 

CUPOLA    LINING   BRICK. 

The  severe  service  to  which  the  linings  of  blast-furnaces  are 
now  subjected,  makes  it  essential  in  a  good  lining  not  only  to 
be  hard  friction,  but  "highly  refractory"  as  well.  Years  ago 
any  brick  that  met  the  first  condition  was  acceptable ;  but  with 
the  practice  of  the  present  day — close-top  furnaces,  improved 


THE   MANUFACTURE   OF   FIRE-BRICK. 


337 


hot  blasts,  high  pressure,  etc. — it  has  become  of  the  greatest 
importance   that   the   brick   used  should   be  highly  refractory. 


BLAST   FURNACE   CRUCIBLE   AND    BOSH. 

The  above  illustration  shows  a  section  of  a  modern  20  foot  furnace.     The  lining  on  one  side  is 
shown  as  built  with  9  and  13%  inch  brick,  the  other  as  formed  with  blocks  lour  inches  thick,  and  in 
length  corresponding  with  the  thickness  of  the  wall.     The  9  and  13%  inch  brick  the  manufacturers 
aim  always  to  have  in  stock;  the  blocks  are  only  made  to  order. 
22 


338 


BRICK,  TILES    AND   TERRA-COTTA. 


To  make  a  lining   possessing  these  qualities  requires  not  only 
that  the  stock  used  be  of  the  best  quality,  but  that  the  mechani- 


FIG.  115. 


PLAN  OF 


FURNACE  Borrow. 


Section  atAB 

BLAST  FURNACE  BOTTOM  BLOCKS. 

The  engraving  as  shown  in  Fig.  115  will  give  an  accurate  idea  of  the  construction  of  The  Har- 
bison &  Walker  Co.  furnace  bottom.  The  lines  forming  each  of  the  four  sides  of  each  block  are 
radials  from  a  given  center,  making  a  perfect  key  out  of  each,  and  thus  effectually  preventing  all 
danger  from  "  floating." 

It  will  be  noted  how  completely  the  upper  course  breaks  the  joints  of  the  course  underneath,  the 
same  blocks  being  used  in  each. 

Three  courses  of  these  blocks  are  used  in  most  of  the  large  furnaces,  and  in  others  from  one  to  two. 


THE   MANUFACTURE   OF   FIRE-BRICK. 


339 


cal  structure  of  the  clay  be  such  as  to  permit  its  being  worked 
into  a  compact  body.  With  these  given,  however,  there  may 
be  an  entire  failure  in  making  a  hard-friction  brick,  so  much  is 
there  depending  upon  the  proper  manipulation  of  the  clays  and 
the  burning  of  the  brick. 

The  nature  of  the  service  required  of  the  brick  in  the  differ- 
ent parts  of  the  furnace  differs  so  widely,  that  no  single  brand 
of  brick  can  be  made  to  answer  all  purposes. 

FIG.  1 1 6. 


14  INCH  AFT  BOILER  TILE. 

Sizes  kept  on  hand: 

12  inch  aft. 

13  inch  aft. 
10  inch  aft. 


12  INCH  CENTER  BOILER  TILE. 

8  inch  center.         n  inch  center. 

9  inch  center.         12  inch  center. 
10  inch  center.         13  inch  center. 

14  inch  center. 


BOILER  TILE. 
12  INCH  SIDE  BOILER  TILE. 

Sizes  kept  on  hand: 
10  inch  side.         14  inch  side. 
12  inch  side.         16  inch  side. 

In  speaking  of  this  subject  The  Harbison  &  Walker  Co.,  of 
Pittsburgh,  Pa.,  say: 

"  Our  practice  for  many  years  has  been  to  make  three  grades 
of  brick,  each  adapted  to  a  particular  part  of  the  furnace. 
'  Benezet '  is  always  used  in  the  bottom,  hearth,  and  bosh ; 
*  Clarion '  in  the  lining  above  the  bosh,  and  '  No.  2  Star 'in  the 


340  BRICK,  TILES    AND   TERRA-COTTA. 

» 

FIG.  117.  FIG.  1 1 8. 


STOVE  LINING. 


SET  OF  24  INCH  GRATE  BACKS. 
Sizes  kept  on  hand : 

l8  X  10  X  2%  22  X  12  X  2% 

l8  X  12  X  2%  24  X  10  X  2% 

20  X  10  X  3%  24  X  12  X  2% 

20  X  12  X  2^  26  X  10  X  2% 

22  X  10  X  2%  26  X  12  X  2% 


FIG.  119. 


THE    MANUFACTURE   OF   FIRE-BRICK. 


top.  All  the  brick  are  plainly  branded  to  avoid  any  inter- 
change of  stock. 

"  We  are  confident  that  the  best  results  will  be  secured  by 
using  the  block  or  tile-lining  above  the  bosh.  Such  is  nearly 
the  uniform  practice  at  the  present  time.  In  the  hearth  ^ind 
bosh  9  and  13  J^-inch  brick  are  generally  used.  For  the  hearth 
and  lower  part  of  the  bosh,  these  answer  every  purpose ;  but 
for  the  upper  part  of  the  bosh,  we  think  the  blocks  will  do 
better. 

"  To  meet  emergiencies  a  large  number  of  these  brick  are  car- 
ried in  stock  of  each  of  the  three  grades  of  stock  necessary  in 
a  lining  :  '  Benezet,'  '  Clarion,'  and  '  No.  2  Star.'  Block  or  tile 

FIG.  119  {Continued*}. 


RAILROAD    SPECIALTIES    (CONTINUED). 

The  illustration,  Fig.  119,  shows  the  more  common  varieties  of  locomotive  blocks  for  fire-box  arches. 
In  No.  i  the  arch  is  formed  by  three  blocks  running  from  front  to  back,  and  keyed  together  on  the 
sides  of  the  block. 

No.  2  is  formed  with  six  blocks,  three  on  each  side,  meeting  over  the  center  of  the  box,  and  secured 
by  a  square  key. 

No.  3  is  also  formed  with  six  blocks,  put  together  in  the  same  way  as  No.  2;  but  instead  of  being 
supported  by  brackets  on  the  side  of  the  fire-box,  as  in  No.  i  and  No.  2,  these  have  recesses  formed  in 
the  ends  of  the  blocks  to  receive  the  bracket. 

linings,  however,  are  only  made  to  order,  as  it  is  necessary  to 
adapt  the  form  of  the  blocks  to  each  particular  furnace.  It  is 
important,  therefore,  that  those  using  such  a  lining  should  an- 
ticipate their  wants  by  ordering  two  to  four  months  in  advance." 


342  BRICK,  TILES   AND   TERRA-COTTA. 

The  manufacture  of  blocks  and  tiles  requires  great  care,  par- 
ticular caution  being  exercised  to  see  that  the  mixtures  of  the 
clays  and  calcine  are  in  correct  proportions.  To  agree  with 
the  shrinkage  allowed  for  in  the  molds  as  being  exact  and  uni- 

FlG.  120. 


COKE    OVEN    WORK. 

The  above,  Fig.  120,  represents  The  Harbison,  Walker  Co.'s  coke  oven  work;  the  upper  half  of 
drawing  representing  a  section  through  the  middle  of  oven,  the  lower  part  being  one-half  of  the  ground 
plan  showing  the  front  opening.  The  9-inch  brick  used  in  this  work  are  shown  in  the  cuts  on  an- 
other page,  and  all  the  shapes  used  are  indicated  in  the  drawing,  as  follows: 

R— Ring,  or  Oven  Vent.  S— Skew  Back.  R  W— Ring  Wall  Brick. 

A — Small  Jamb.  i  to  6 — Door  Arch.  T — Bottom  Tile  (10  x  10  x  4). 

B — Large  Jamb.  C — Crown  Brick. 

form  to  size  ordered,  it  is  important  to  have  this,  as  it  is  neces- 
sary that  the  clay  should  be  ground  regularly  as  to  stiffness ; 
great  care  is  also  required  in  dressing  the  tiles  when  suf- 


THE   MANUFACTURE   OF   FIRE-BRICK. 


343 


ficiently  hard  to  handle,  seeing  that  not  only  the  tiles  are 
smooth  and  level  on  the  face  and  sides,  but  also  that  the  edges 
are  s-harp ;  the  tile,  when  finished,  being  equal  in  appearance 
to  a  wood  block  the  same  size  and  shape. 


FIG.  121. 


GAS   WORKS. 

The  above  drawing  shows  the  tiles  and  blocks  necessary  in  setting  a  bench  of  fire  clay  retorts,  as 
follows: 

6  pieces  of  No.  i,  5  inches  thick.  6  pieces  of  No.  5,  5  inches  thick. 

12  pieces  of  No.  2,  5  inches  thick.  12  pieces  of  No.  6,  5  inches  thick. 

12  pieces  of  No.  3,  5  inches  thick.  6  tiles,  14  x  14  x  2  inches,  No.  7. 

12  pieces  of  No.  4,  5  inches  thick.  6  tiles,  12  x  14  x  2  inches,  No.  7. 

1 8  feet  of  corner  pieces  for  each  retort,  No.  8. 

One  defect  in  making  large  tiles  or  blocks — that  is,  those 
containing  more  clay  than  the  moulder  can  handle  and  put  in 
the  mould  at  one  time — is  that  in  preparing  it  on  the  table  it  is 


344 


BRICK,  TILES   AND   TERRA-COTTA. 


rolled  in  sand.  Two  or  more  separate  balls  of  clay  coining  to- 
gether in  the  same  mould  are  liable  to  make  and  leave  what 
are  termed  sand-cracks,  the  sand  preventing  the  clay  .from 
being  properly  united  together  in  the  mould ;  the  tile  or  block 
in  such  case  coming  out  of  the  kiln  cracked  or  broken,  and  in 


FIG.  122. 


FIG.  123. 


COVER  TILE.      FOR  STEEL  COKE  HOLDERS. 

FIG.  124. 


13 


RABBETED  TILE  FOR  GREENHOUSES, 
FLUES,  ETC. 

Sizes  kept  on  hand: 

13  x  13  x  2%.  13  x  15  x  2%. 


SLABS  AND  STEAMBOAT  BRIDGE  WALL 
TILE. 

Sizes  kept  on  hand: 

18  x  12  x  2.     24  x  12  x  3. 

18  x  12  x  3.     18  x  14  x  3. 

24  x  14  x  3. 


place  of  being  salable  goes  back  to  the  mill.  A  machine  for 
making  tiles  and  blocks  is  now  in  use,  which  not  only  does 
away  with  these  sand-cracks,  but  also  makes  more  solid  and 
better  work  at  less  cost.  This  machine  is  in  all  respects  the 
same  as  the  smaller  size  sewer-pipe  press,  only  that  in  place  of 


THE   MANUFACTURE    OF   FIRE-BRICK.  345 

the  die  a  box  is  bolted  to  the  bottom  with  a  flat  plate  around 
the  outside  of  the  bottom  of  the  box.  Below  this  is  another 
iron  plate  or  table  underneath,  and  in  the  center  of  which  it  is 
connected  with  a  screw  secured  to  framing  in  the  floor;  on  the 
screw  are  four  cross-handles  for  working  the  same.  The  mould, 
after  being  sanded,  is  placed  on  the  bottom  plate,  the  screw 
given  a  turn,  tightening  the  mould  up  to  the  top  plate,  the 
lever  is  pulled  as  in  making  sewer-pipe,  forcing  the  clay  into 
the  mould,  the  pressure  being  sufficient  to  force  the  clay  past 
the  box  and  under  the  bottom  of  the  top  plate  to  the  sides  and 
ends  of  the  mould ;  the  steam  being  then  cut  off  by  the  lever, 
the  screw  is  again  given  a  turn,  liberating  the  mould  from  the 
upper  plate  sufficiently  to  allow  the  cut-off  wire  to  be  drawn 
between  the  top  of  the  mould  and  the  underside  of  the  plate. 
The  mould  is  then  drawn  out  on  to  a  block  at  one  side  to  be 
struck  or  planed  and  another  mould  run  between  the  plates  as 
before  mentioned.  In  this  way  of  making  blocks  and  tiles 
every  one  is  perfect  and  comes  out  of  the  kiln  perfectly  sound. 
This  plan  of  making  fire-clay  blocks  and  tiles  is  recommended 
to  such  of  our  readers  as  are  large  makers,  and  to  manufac- 
turers who  have  not  heretofore  cared  to  make  locomotive  and 
similar  tiles  on  account  of  the  great  loss  arising  from  the  reasons 
before  described. 

FIRE-BRICK    WORKS    AND    THEIR    CONSTRUCTION. 

The  arrangement  or  plan  upon  which  a  fire-brick  works 
should  be  built  is  of  the  first  importance.  Any  person  con- 
versant with  the  business  will  notice  in  traveling  through  the 
different  parts  of  the  country  and  inspecting  the  various  plants, 
the  varied  styles  adopted,  and  not  unusually  the  entire  absence 
of  arrangement  and  the  many  disadvantages  under  which  the 
proprietors  of  such  works  are  laboring,  and  which  disadvantages 
might  have  been  obviated.  This  is  in  some  degree  due  to  the 
fact  that  in  the  first  instance  a  small  plant  only  was  contem- 
plated and  built,  and  not  making  any  provision  for  extensions. 
In  the  erection  of  a  new  fire-brick  works,  the  first  subject  re- 


346  BRICK,  TILES    AND   TERRA-COTTA. 

quiring  attention  is  the  amount  of  capital  at  disposal.  This 
question  having  been  satisfactorily  settled,  one-third  of  that 
amount  should  be  set  aside  as  working  capital.  In  default  of 
this  precaution  you  commence  with  difficulties,  and  continue  to 
labor  under  them  until  your  credit  is  gone.  The  works  shut 
down,  some  other  persons  come  in  and  buy  them  at  about  one- 
third  the  cost,  and  reap  the  advantages  you  had  anticipated. 
Our  trade  papers  reveal  this  fact  in  almost  every  issue. 

The  next  point  is  to  get  a  plan  drawn,  not  just  of  the  works 
you  propose  to  build,  but  considerably  larger,  and  particularly 
as  regards  dry-floors  and  kilns ;  taking  also  into  account  stock 
room  for  clay  and  brick  for  an  increased  output.  You  can 
then  build  as  much  of  the  plant  as  your  capital  will  permit  or 
circumstances  justify,  so  that  as  your  business  is  a  success  and 
you  see  your  way  clear  to  extend  the  works,  then  you  can  carry 
out  a  further  portion  of  your  original  plan.  In  following  this 
course,  your  works  are  convenient  and  uniform.  You  should 
always  in  the  first  instance  put  down  your  machinery,  including 
engine  power,  in  excess  of  your  present  requirements,  to  be 
prepared  for  this  extension.  The  usual  way  is  to  calculate  how 
little  horse-power  you  can-  manage  to  do  with,  and,  when  you 
make  an  extension,  engine  and  boiler  will  be  sold  at  a  sacrifice 
to  make  room  for  a  power  plant  of  larger  capacity.  The  differ- 
ence or  loss  between  the  latter  and  former  policy  would  build  a 
new  kiln  or  dry-floor. 

In  drawing  plans  for  a  new  works,  in  order  to  secure  every 
convenience  and  economy  in  labor,  you  must  arrange  your 
plant  so  that  your  material  always  travels  in  one  direction ; 
that  is,  from  the  clay-bank  to  brick  in  car  or  stock-house ;  thus 
clay-bank,  mill,  moulding  side  of  dry  floor,  pressing  side  of  dry 
floor,  kilns,  railroad,  stock-house — a  straight  line  would  run 
across  each  in  the  order  named.  The  buildings  containing  the 
engine  and  mills  should  be  separate  from  the  moulding-room, 
but  attached  to  the  same  on  the  outside,  so  that  the  pug-pans 
will  be  in  the  centre  of  the  outside  walls.  As  it  is  not  the  ob- 
ject of  this  book  to  advertise  any  particular  machinery  to  the 


THE   MANUFACTURE    OF   FIRE-BRICK.  347 

detriment  of  other  makers,  individual  names  will  not  now  be 
mentioned.  What  we  would  say  is,  before  you  definitely  decide 
as  to  the  type  and  make,  see  the  machine  in  operation  in  suc- 
cessful works,  then  exercise  your  own  judgment. 

As  to  boilers,  on  no  account  buy  a  second-hand  boiler,  for, 
in  risk,  stoppages  and  repairs,  it  would  probably  be  dear  to 
you  as  a  gift.  In  arranging  to  put  down  your  boilers,  allow 
room  for  the  addition  of  one  or  more,  as  you  find  it  necessary 
to  extend  your  plant. 

In  deciding  what  amount  of  engine-power  you  require,  there 
should  be  a  surplus  of  at  least  one -third  more  than  will  ever  be 
required.  The  engine-room  should  be  entirely  separate  in 
order  to  keep  out  the  dust.  A  great  deal  of  the  wear  and  tear 
of  engines  in  fire-brick  works  arises  from  this  oversight.  As 
regards  dry-pans,  there  is  an  equal  difference  in  opinion  as  to 
whether  it  is  best  to  drive  them  with  under  or  over-gearing.  In 
overhead  gearing  on  framework  of  wood  and  iron,  there  is  in- 
variably considerable  oscillation,  resulting  in  loosening  bolts 
and  framework,  and  finally  in  breakage.  Whereas,  in  under- 
geared  mills  the  bearings  are  shorthand  the  strains  are  less  in 
consequence,  the  whole  being  more  rigid  and  firm.  The  ob- 
jection to  undergeared  mills  is,  that  the  driving-gear  being  be- 
low ground-level,  sufficient  room  is  not  left  in  the  bottom  for  a 
man  to  get  around  to  examine  and  oil  the  machinery.  In 
nearly  every  case  where  under-geared  mills  are  put  down  the 
engineer  has  to  crawl  or  creep  under  as  best  he  can,  and  he 
does  this  with  the  bottom  covered  with  black  oil,  and  perhaps 
some  accumulation  of  water  or  dampness  arising  from  imperfect 
drainage.  This  state  of  things  in  connection  with  under-geared 
mills  is  not  imagination ;  it  is  the  invariable  rule,  and  what  is 
the  result?  The  engineer  goes  under  as  seldom  as  possible, 
and  then  not  to  examine,  but  to  reach  as  far  as  possible  with 
the  oil-can;  the  toe  at  the  bottom  of  the  shaft  gets  hot;  the 
machinery  stands  for  it  to  get  cool,  and  so  losses  continue  re- 
peating. 

It  is  best,  where  you  have  the  drainage  to  do  it,  in  putting 


348  BRICK,  TILES    AND   TERRA-COTTA. 

down  an  undergeared  dry-pan  to  get  your  foundations  out  suffi- 
ciently deep  with  walls  around  the  same  so  that  the  engineer 
can  go  down  the  steps  and  walk  all  around.  He  will  then  not 
only  go  down  more  frequently,  but  will  be  able  and  disposed  to 
examine  the  same.  This  little  extra  expense  in  depth  will  be 
the  best-saved  money  you  can  make  in  the  building  of  your 
works.  If  you  can  get  the  drainage  and  this  extra  depth  is 
given,  the  undergeared  dry-pan  is  by  far  the  best.  If  you  can- 
not get  the  necessary  drainage  and  put  it  down  in  the  way  de- 
scribed, then  the  overhead  arrangement  is  preferable. 

From  the  dry-pan  we  next  come  to  the  elevators  and  wet- 
pan.  In  examining  many  fire-brick  works  we  see  the  same 
primitive  way  of  wheeling  the  clay  from  the  wet-pan  to  the 
tables,  which  means  additional  men  and  the  space  occupied  by 
the  runs  on  the  dry-floor  lost.  Amongst  the  improvements  of 
modern  fire-brick  works  may  be  mentioned  the  clay  belt — a 
description  of  which  will  probably  be  interesting  to  those  who 
have  not  seen  it  in  operation — the  moulders'  tables  being  all 
along  and  in  line  with  the  wall,  as  also  the  wet-pan.  A  belt 
conveyor  runs  along  the  side  of  pan  and  tables  at  a  sufficient 
height  above  the  latter,  so  as  to  leave  ample  room  for  the  de- 
livery of  the  clay.  On  each  side  of  the  belt  are  wood  sides,  in 
the  bottom  of  which  are  affixed  rollers  on  which  the  belt  travels. 
In  these  wood  sides  opposite  each  moulding-table  is  a  gate ; 
that  is,  a  piece  of  the  side  is  cut  out  and  attached  in  place  again 
with  a  pair  of  hinges,  so  that  it  can  be  opened  across  the 
trough  just  over  the  belt.  The  gate  being  longer  than  the 
width  of  the  trough,  it  will  open  at  an  angle  of  about  45°.  The 
mill  man  discharges  a  pan  of  clay  on  the  belt,  the  sides  keeping 
it  in  place — a  boy  in  charge  of  the  belt  opens  a  gate  opposite 
one  of  the  tables ;  the  clay  coming  into  contact  with  it  at  the 
angle  before  named,  slides  along  it  and  off  the  belt  on  to  the 
table.  The  boy  then  closes  the  gate,  closing  up  the  side,  and 
opens  the  gate  opposite  the  next  table  to  receive  the  following 
charge,  and  so  in  rotation.  Where  seen  in  work,  this  belt  was 
supplying  clay  for  five  tables  and  a  machine. 


THE    MANUFACTURE   OF   FIRE-BRICK.  349 

Another  plan  of  conveying  the  clay  from  pan  to  tables,  which 
is  still  better,  is  to  empty  the  pan  of  clay  into  a  self-dump  car, 
which  is  then  run  over  a  light  tram-road  over  the  tables  and 
dumped  down  the  chute  at  the  table  where  required.  One  lad 
in  this  way  will  supply  clay  for  20,000  brick  per  day.  The 
point  in  the  latter  method  of  conveying  the  clay  is  to  have  the 
necessary  elevation.  The  way  to  do  this  is  to  take  the  clay  up 
sufficiently  high  when  it  is  in  the  elevators  from  the  dry-pan,  so 
that  the  clay  may  be  delivered  into  the  bins  at  a  height  to  allow 
the  wet  or  pug-pans  to  be  fixed  high  enough  to  discharge  the 
clay  in  the  dump-car.  It  is  much  easier  with  this  arrangement 
to  discharge  the  clay  down  to  the  tables  than  wheel  it  up,  and 
only  requires  a  greater  length  of  elevator-belt  and  to  have  the 
pug  pan  about  four  feet  above  the  upper  floor.  It  is  in  such 
arrangements  as  these  where  the  cost  of  manufacture  is  reduced. 
In  the  construction  of  the  works  we  next  come  to  the  main 
building  or  factory  where  the  brick  are  moulded,  pressed  and 
dried  ;  this  building  will  be  from  sixty  to  seventy  feet  wide  from 
side  opposite  the  mills  and  of  required  length.  The  ends  should 
not  be  permanently  closed,  but  so  put  together  that  any  exten- 
sion may  be  made  at  one  or  both  ends  as  might  be  desired,  and 
so  keep  the  moulding-room  in  one  open  compact  building.  If 
thus  arranged,  the  whole  of  the  work  is  under  the  manager's 
eye  at  one  time.  Where  the  roof  is  high  and  wet-pan  elevated 
as  described,  it  is  advisable  to  economize  what  space  you  can 
in  the  same  by  putting  down  a  floor  over  the  the  posts  sup- 
porting the  roof,  sufficient  flooring  being  put  down  to  make  the 
blocks  and  tiles.  The  heat  from  the  floor  below  will  not  only 
dry  them,  but  will  do  so  very  regularly.  With  respect  to  the 
covering  for  the  roof,  shingles,  felting  of  every  kind,  sheet-iron 
and  galvanized,  corrugated  iron,  have  all  been  tried,  all  of  which 
have  proved  failures  except  shingles.  No  roof  covering  is  more 
severely  tried  than  that  over  a  brick  dry-floor ;  the  heat  and 
steam  continually  rising  and  hanging  under  the  roof  makes  all 
feltings  rotten  and  short,  so  that  they  split  when  the  boards  to 
which  they  are  nailed  expand  or  contract  by  the  action  of  heat 


350  BRICK,  TILES   AND   TERRA-COTTA. 

and  damp.  Sheet  iron  from  the  same  causes  quickly  rusts 
through  and  leaks.  Galvanized  iron  is  but  little  better,  as  the 
coating  peels  off  and  it  then  rusts.  For  a  roof  covering  to  resist 
the  action  of  heat  and  steam  inside  and  sun  and  rain  outside, 
there  is  nothing  equal  to  shingles,  except  a  clay  tile  roof,  which 
would  be  found  too  expensive.  In  connection  with  the  mould- 
ing-room, we  next  come  to  the  important  part  of  it,  viz. :  the 
dry-floor. 

Steam  Drying  Floors. — There  are  various  systems  of  drying 
brick  with  exhaust  steam  from  the  engine  or  steam  direct  from 
the  boilers,  and  several  fire-brick  works  have  now  in  use  dry- 
floors,  in  which  are  laid  parallel  rows  of  one-inch  iron  pipe, 
over  which,  in  some  cases,  is  laid  a  floor  of  cement.  In  some 
plants,  fresh  blast-furnace  slag  with  a  small  addition  of  lime  is 
ground  in  the  mill,  and  when  laid  over  the  pipes  is  run  over 
with  a  roller;  the  latter  plan  has  been  found  to  be  more  satis- 
factory, as,  while  making  a  floor  equally  as  smooth  and  hard  as 
cement,  it  is  not  so  liable  to  crack  from  the  effects  of  the  heat. 

One  difficulty  met  with  in  this  system  of  dry-floor  is  the 
expansion  and  contraction  of  the  iron  pipes  in  consequence 
of  their  being  at  one  time  hot  and  another  cold.  Several 
methods  have  been  adopted  to  counteract  this.  The  most  suc- 
cessful one  is  to  bury  the  pipes  in  loose  sand  before  covering 
them  over  with  the  permanent  floor,  thus  allowing  the  pipes  to 
draw  without  breaking  the  floor. 

Manufacturers  who  have  adopted  this  plan  of  drying  speak 
in  very  satisfactory  terms  of  the  result. 

There  is  another  steam  dry-floor  much  more  economical  in 
working  and  far  more  satisfactory.  It  is  extensively  used  in 
England,  a  description  of  which  will  be  of  interest: 

Parallel  brick  walls  four  and  a  half  inches  thick  are  built 
across  the  dry-floor  to  receive  the  metal  floor-plates  much  after 
the  manner  of  flue  walls  to  receive  tiles,  except  that  in  order  to 
have  a  thorough  control  over  the  temperature  of  the  floor  the 
steam  flues  are  divided  off  into  sections ;  the  outside  wall  of 
each  section  is  built  tight  or  with  close  joints,  the  intermediate 


THE   MANUFACTURE    OF   FIRE-BRICK.  351 

flue  walls  being  built  open-work  or  pigeon-holed,  the  ends  of 
the  brick  being  about  two  inches  apart. 

This  is  in  order  that  one  pipe  from  the  main  exhaust  may  be 
sufficient  for  each  section.  In  connection  with  this  portion  of 
the  work  it  must  be  said  the  brick  should  be  set  in  cement, 
as  lime  would  be  affected  by  the  steam. 

It  is  also  necessary  that  consideration  should  be  given  to 
allow  for  the  escape  of  the  condensed  water;  the  under  floor  of 
the  flues,  having  been  made  water-tight  by  a  covering  of  cement, 
should  have  a  slight  fall  towards  the  point  most  suitable  for  the 
condensed  water  to  escape  or  be  collected  in  a  cistern  for  return 
to  boiler,  which  is  preferable,  as  this  water  is  not  only  pure,  but 
also  warm. 

These  walls  are  covered  with  metal  floor-plates  ;  a  useful  size 
being  24  inches  by  30  inches,  and  half  inch  thick,  or  three-eighths 
would  be  sufficient  when  you  can  get  them  cast  that  thickness 
without  twisting.  A  light  rib  on  the  under  side  of  the  plate 
running  through  the  center  from  each  of  the  four  corners  will 
meet  this  difficulty. 

Around  the  sides  and  ends  of  each  plate  is  cast  a  light  flange, 
extending  below  the  under  side  three-quarters  of  an  inch.  This 
flange  will  sink  into  the  cement  when  placed  in  the  work  and 
help  to  make  a  steam-tight  joint. 

Several  attempts  have  been  made  to  adopt  this  floor  in  this 
country,  which  have  proved  failures,  owing  to  the  lack  of  knowl- 
edge how  to  make  them  steam  tight.  For  successful  ones  the 
writer  would  refer  those  interested  to  the  Akron  Fire-Brick 
Works,  Akron,  Ohio,  where  they  can  be  seen,  and  as  free 
from  leakage  as  the  boiler  itself.  The  flue  walls  having  been 
built  and  the  tops  trued  with  a  string  line,  the  bottoms  made 
water-tight  with  cement  that  the  water  may  flow  away  in 
place  of  draining  into  the  ground  and  damaging  the  founda- 
tions, then  proceed  to  lay  the  plates  by  first  placing  across 
the  flue-walls  rods  of  one  and  a  half  inch  JL  iron  the  distance  apart 
of  the  length  of  the  plates.  After  these  have  been  filled  wich 
cement  to  receive  the  ends  of  the  plates  and  the  walls  covered 


352  BRICK,  TILES   AND    TERRA-COTTA. 

with  cement  for  the  sides,  then  lay  down  the  plates,  always 
being  careful  that  the  end  3  and  sides  of  the  plates  fit  tightly 
together.  This  full  description  of  laying  is  necessary,  because 
if  carefully  adopted  it  will  prevent  leakage  and  render  practi- 
cable the  best  dry-floor  that  can  be  put  down. 

The  main  exhaust  steam-pipe  should  be  taken  from  the  top 
of  the  water-heater  connected  with  the  boiler,  and  continued 
overhead  through  the  middle  of  the  dry-floor  and  across  the 
line  of  flues,  branches  from  which  at  the  center  of  each  section 
right  and  left  should  connect  with  the  steam-flues. 

In  each  branch  is  fitted  a  valve,  by  means  of  which  each 
separate  section  can  be  made  hot  or  cold  or  any  intermediate 
state  as  required.  This  is  one  of  the  advantages  which  this 
system  possesses ;  another  is  that  the  steam  is  turned  directly 
into  the  flues,  and  has  only  the  thickness  of  the  plate  between 
the  steam  and  the  brick  being  dried ;  the  floor,  when  the  valve 
is  fully  opened,  being  too  hot  to  bear  the  hand  upon.  It 
should  be  stated  that  in  connecting  the  exhaust  pipe  to  the 
heater  at  boiler  into  which  the  exhaust  is  discharged  from  the 
engine,  a  branch  pipe  should  be  connected  and  passed  through 
thereof;  on  the  top  of -this  pipe  attach  a  sheet-iron  lid  on 
hinges,  so  that  in  case  too  many  of  the  valves  in  the  dry-room 
are  closed,  the  steam  will  lift  the  lid  and  escape,  thus  prevent- 
ing any  back  pressure  on  the  engine. 

The  advantages  of  this  steam  dry-floor  over  any  other,  in 
addition  to  the  control  over  the  distribution  of  the  steam  in 
the  various  sections  as  required,  and  the  regulation  of  heat 
necessary  as  before  described,  are  that  the  exhaust  steam  is 
sufficient  to  provide  all  heat  required  for  the  dry-floor;  and 
should  any  of  the  sections  require  heat  after  the  engine  has 
stopped  work,  an  inch  pipe  can  be  connected  from  the  boiler 
with  the  main  exhaust,  and  thus  utilize  the  steam  left  in  the 
boiler. 

The  main  feature,  however,  is  that  after  the  first  expense  of 
laying  this  floor  has  been  paid,  the  drying  of  the  brick  does 
not  cost  one  cent.  The  fact  that  all  the  brick  manufactured 


THE    MANUFACTURE    OF   FIRE-BRICK.  353 

can  be  dried  ready  for  kiln  free  of  cost  should  attract  and   en- 
gage the  attention  of  all  manufacturers. 

Another  advantage  is  a  perfectly  smooth  and  level  floor,  not 
only  allowing  the  brick  and  tiles  to  be  straight  and  true  but  also 
preventing  the  breakage,  if  not  on  the  dry-floor,  in  the  kiln,  in 
consequence  of  the  brick  being  not  true  to  shape.  One  more  im- 
portant feature  possessed  by  this  steam-floor  over  the  old  sys- 
tem of  fire  flues  is  the  absence  of  fire  and  the  risk  of  being 
burned  out,  which  so  frequently  is  the  case;  this  should  reduce 
the  rate  of  insurance.  It  can  also  be  mentioned  that  in  steam- 
drying  everything  is  clean,  there  being  no  ashes  to  wheel  away 
or  accumulate. 

Objections   have  been  raised  to  this  plan  of  steam-drying  in 
consequence  of  what  appears  to  be  its  heavy  cost  as  compared 
with  the  dry-floors  generally  used.     Do  not  be   prejudiced  at 
first  sight.     This  system   is  worthy  of  a  careful  investigation. 
Take  a  pencil   and  make  a  calculation  in  .this  manner  when  in- 
tending to  put  down  a  new  dry-floor:    first,  estimate  the   cost 
of  this  steam-floor  as  described;   that  done,  get  the  cost  of  the 
old  style  dry-floor  you   proposed  to  $ut  in ;   then  ascertain  the 
cost  per  month  of  coal   and   labor  required  for  the  same,  and 
figure  out  how  many  months   cost  of  coal  and  labor  it  would 
take  if  added  to  the  cost  of  the  fire-flue  floor  to  equal  the  cost 
of  the  steam-floor.     You  would  find  it  would  be  from  twelve  to 
eighteen  months,  according  to  the  price  of  your  fuel.     When 
that  point  is  reached  your  cost  of  fuel  and  labor  continues,  while 
that  of  the  steam-floor  is  practically  nothing,  in  addition  to  the 
many  other  advantages  already  alluded  to.     Economy  in  man- 
ufacture is  in  doing  a  little  well  and  reducing  the  cost  of  pro- 
duction to  the  lowest  possible  point,  rather  than  in  trying  to 
spread  your  limited  capital  over  the  largest  extent  of  plant  pos- 
sible.    The  plan  generally  adopted  in  the  erection  of  fire-brick 
works  is  for  the  amount  of  capital  at  command  to  get  the  great- 
est output  of  brick,  which  means  increased  cost  of  production, 
in  place  of  considering  the  most  modern  and  economical  sys- 
tems of  manufacture,  although  they  may  be  more  costly  and  the 
23 


354  BRICK,  TILES   AND   TERRA-COTTA. 

output  of  brick  for  the  same  amount  of  capital  less.  Your  brick 
will  be  of  better  quality,  commanding  a  larger  price,  your 
profits  also  larger,  thus  enabling  you  in  a  short  time  to  extend 
your  plant  on  the  same  principles,  and  thus  you  will  find  you 
are  sailing  with  the  wind,  instead  of  against  it  as  in  the  former 
and  general  way. 

Turley  &  Beyerly's  Dry- Floor, — The  Kentucky  Fire  Brick  Co., 
Portsmouth,  Ohio,  has  had  in  satisfactory  use  for  over  a  year  a 
drying  system  in  its  new  fire-brick  plant  for  the  drying  of  all 
"  shape  work."  The  brick  made  upon  this  floor  are  claimed  to 
be  firmer,  and  it  is  also  claimed  that  the  breakage  is  not  five  per 
cent,  of  the  loss  by  the  old  process  of  flue  drying.  This 
method  of  drying  fire-clay  wares  is  very  economical.  The 
pipes  have  not  in  any  instance  leaked.  The  circulation  and 
drainage  are  also  claimed  to  be  perfect.  This  drying-floor  is 
the  invention  of  Leslie  C.  Turley  and  William  G.  Beyerly,  of 
Portsmouth,  Ohio,  from  whom  all  desired  information  can  be 
obtained.  This  brick  drying-floor  was  patented  in  the  United 
States  October  2/th,  1891,  the  number  of  the  patent  being 

487,554. 

Hot- Air  Drying  Floors^ — In  Fig.  126  is  illustrated  a  form  of 
hot-air  drying  floor  which  is  in  use  in  the  various  plants  of  the 
Glenboig  Union  Fire  Clay  Co.,  Limited,  of  Glasgow,  Scotland, 
and  which  is  suitable  for  the  drying  of  either  fire-brick  or  sewer 
pipe. 

It  enables  a  manufacturer  to  put  two  moulders  in  the  space 
usually  allotted  to  one,  and  it  completely  does  away  with  the 
"  hot  end  "  and  the  consequent  cracking  of  goods  dried  near 
the  firing  ends.  At  Glenboig  they  use  iron  plates  (flasked 
castings),  each  4  feet  by  2  feet  by  ^  inch,  but  fire-clay 
covers  (slabs)  can  be  used.  These  plates  are  secured  in  posi 
tion  at  their  joints  on  cross-plates,  whose  breadth  is  about  that 
of  a  brick,  and  by  this  arrangement  all  possibility  of  dust  get- 
ing  through  to  choke  the  subjacent  fires  is  effectually  pre- 
vented. Besides  the  increased  production  from  a  given  size  of 
drying-floor,  the  firing  is  safer  and  more  regular,  and  the  first 


THE   MANUFACTURE   OF   FIRE-BRICK. 


355 


356  BRICK,  TILES    AND   TERRA-COTTA. 

cost  is  greatly  reduced,  as  air  space  takes  the  place  of  fire-clay 
slabs  in  a  large  portion  of  the  floor.  The  illustration  in  Fig. 
126  gives  a  good  idea  of  the  construction  of  the  floor. 

These  drying  floors,  or  "  drying  stoves,"  as  they  are  called 
in  Great  Britain,  are  each  120  feet  long  by  36  feet  wide. 

Although  the  stoves  are  fired  from  one  end,  there  is  a  uni- 
form temperature  maintained  in  them  throughout  their  whole 
extent.  This  result  is  accomplished  by  having  an  arrangement 
of  double  floors,  with  cold-air  passages  between  them  half  way 
up  the  stove.  By  this  system  of  heating  Mr.  Dunnachie  ob- 
tains the  most  perfect  control  of  the  temperature  of  the  stoves, 
even  though  an  iron  floor  is  used,  an  object  long  aimed  at  and 
often  attempted,  but  'now  successfully  accomplished.  In  ordi- 
nary practice  there  is  no  deterioration  of  the  brick.  No  over- 
heating takes  place,  consequently  no  cracking  of  the  brick,  and 
therefore  they  go  far  sounder  to  the  kiln  than  is  usually  the 
case.  Owing  to  the  special  mode  of  arranging  the  dampers, 
each  stove  can  be  worked  in  stripes,  to  be  strongly  heated,  if 
necessary,  or  mildly  when  sharp  firing  is  not  desirable. 

Owing  to  the  successful  way  in  which  the  drying  operation 
is  conducted,  those  brick  which  are  made  one  day  are  ready 
the  next  day  for  the  kiln,  whither  they  are  at  once  carried 
direct  without  any  piling.  As  there  is  thus  no  unnecessary 
handling,  the  chipping  or  other  injury  which  brick  frequently 
meet  with  while  unfired  or  in  the  green  state  is  reduced  to  a 
minimum. 

The  air-flue  at  front  is  closed  by  a  slab,  which  is  tilted  around 
so  as  to  make  the  opening  large  or  small,  as  may  be  required. 
This  is  a  better  and  cheaper  arrangement  than  a  close  door. 

Some  of  the  older  fire-brick  works  in  the  States  of  Ohio  and 
Pennsylvania  have  in  use  hot-floors,  which  are  constructed  as 
follows :  Across  the  end  of  the  floor,  which  is  nearly  always 
rectangular,  is  dug  a  pit  some  six  feet  below  the  general  level. 
In  the  wall  of  this  pit  are  set  fireplaces  at  intervals  of  from  five 
to  six  feet.  The  fireplaces  proceed  inward  about  a  yard,  and 
then  break  up  into  from  three  to  five  parallel  flues.  These 


THE   MANUFACTURE   OF   FIRE-BRICK.  357 

flues  are  about  ten  inches  square,  and  are  separated  by  four 
inches  of  brick.  The  flues  traverse  the  whole  distance  of  the 
floor  and  unite  in  a  chimney  or  chimneys  at  the  other  end, 
which  must  be  high  enough  to  make  every  individual  flue  draw. 
These  flues  are  covered  by  square  tile  twelve  inches  on  a  side ; 
the  tile  are  placed  four  thick  at  the  fire  end  of  the  flue,  and  run 
down  to  one  tile  at  the  opposite  end.  This  is  done  to  equalize 
the  heat  of  the  floor.  The  depth  of  the  flues  is  so  arranged 
that  their  unequal  covering  brings  the  tile  to  a  level  plane ;  on 
this  is  spread  a  cement  adapted  to  this  use ;  it  is  made  of  basic 
furnace  cinder  and  sandy  clay  in  equal  parts,  ground  fine,  and 
wet.  If  the  cinder  is  not  basic  enough,  lime  is  added ;  the 
mixture  sets  very  hard,  and  will  last  four  or  five  years  if  well 
treated.  Sometimes  the  flues  are  covered  with  one  thickness 
of  tile  all  over,  and  are  then  leveled  up  with  sand  and  another 
layer  of  tile.  This  is  undoubtedly  cheaper,  and  is  also  as  even 
a  distributor  of  heat  as  a  plain  tile  floor  would  be,  but  is  rather 
more  apt  to  cause  trouble  in  repairing  by  blocking  up  the  floors 
with  sand. 

Conveying  Fire-Clay.  The  most  economical  and  expeditious 
methods  of  handling  fire-clay  at  the  mines,  and  conveying  it 
from  the  mine  to  the  factory,  are  of  great  importance,  as  the 
continuous  operation  of  work  during  both  winter  and  summer 
often  depends  on  the  means  used  to  transport  the  clay. 

The  Union  Mining  Company,  Mount  Savage,  Md.,  has  had 
much  experience  in  the  handling  of  fire-clay.  The  clay  mine 
of  that  company  is  situated  on  the  south  side  of  Savage  Moun- 
tain, three  miles  from  the  works  by  the  tramroad.  The  bed  of 
clay  crops  out  along  the  summit  of  the  mountain,  and  runs 
nearly  northeast  and  southwest.  The  only  other  mine  on  this 
bed  is  a  very  small  one,  two  miles  from  that  of  the  Union  Min- 
ing Company.  The  clay  from  this  mine  is  brought  to  Frost- 
burg,  where  it  is  manufactured  into  brick. 

The  large  bed  was  first  opened  on  the  out-crop,  and  for  a 
number  of  years  all  the  clay  was  dug  from  open  pits,  and 
hauled  at  great  expense  down  the  mountain  in  wagons  to  the 


358  BRICK,  TILES   AND   TERRA-COTTA. 

works.  Finally,  when  this  method  of  mining  had  been  carried 
on  as  long  as  was  economical,  the  mine  began  to  be  worked 
systematically,  and  the  levels  were  driven  on  the  out-crop,  on 
one  side,  wherever  it  could  be  reached  by  reason  of  the  forma- 
tion of  the  hill.  From  this  level,  galleries  were  driven  at  an 
angle  up  on  the  bed,  clear  through  to  the  old  workings. 
Chambers  were  driven  out  from  these  galleries,  connecting  the 
galleries  as  often  as  the  ground  would  permit.  When  these 
chambers  are  all  driven  through,  that  part  of  the  mine  is 
robbed  of  as  many  of  the  pillars  between  the  chambers  as  it  is 
practicable  and  safe  to  remove.  There  are  several  of  these 
levels  driven,  the  last  one  about  100  feet  below  the  next  above, 
and  as  the  bed  dips  about  one  foot  in  every  four  on  an  average, 
one  can  calculate  on  the  amount  of  clay  each  level  will  yield. 
From  the  present  outlook  there  is  enough  to  run  the  works  for 
a  great  many  years. 

At  the  time  this  more  systematic  mining  was  begun,  some 
cheaper  mode  of  transportation  was  also  sought.  First,  a  wire- 
tram  on  the  English  system  was  tried,  consisting  of  an  endless 
wire  rope,  with  buckets  of  the  capacity  of  fifty  pounds,  and  a 
stationary  engine  of  So-horse  power  at  the  bottom.  This  plan 
involved  much  trouble,  and  never  could  supply  the  requisite 
amount  of  clay ;  and  when  winter  came,  with  its  extreme  cold 
and  snow,  the  plant  was  practically  useless.  Then  the  regular 
three-rail  incline  was  adopted,  which  is  in  common  use  in  this 
coal  region,  and  which  has  worked  well  ever  since.  The  only 
peculiarity  of  this  incline  is  its  great  length.  It  is  a  mile  and  a 
quarter  long,  and  the  rise  from  the  bottom  to  the  top  is  1,240 
feet.  Six  cars  run  up  it  at  a  time;  three  loaded  ones  coming 
down  haul  up  the  three  empty  ones.  The  rope  is  of  steel,  and 
five-eighths  of  an  inch  in  diameter,  and  runs  over  two  shrive 
wheels  twelve  feet  in  diameter,  on  each  of  which  is  a  hand- 
brake. One  man  to  run  these  brakes,  two  men  to  load,  one 
man  to  unhook  at  the  bottom,  and  one  to  look  after  the  rollers 
on  the  incline,  are  all  that  are  necessary  to  run  100  tons  of  clay 
per  day.  The  cars  when  empty  weigh  1,800  pounds,  and  two 


THE    MANUFACTURE   OF   FIRE-BRICK.  359 

tons  of  clay  are  loaded  on  each  car.  It  takes  seven  minutes, 
on  an  average,  to  run  one  trip.  This  is  said  to  be  the  longest 
gravity  road  of  its  kind  in  the  world.  From  the  bottom  of  this 
inclined  plane  a  tramroad  is  built,  two  miles,  to  the  factories  at 
Mount  Savage,  and  a  substantial  narrow-gauge  locomotive 
placed  upon  it  brings  all  clay  direct  to  the  factory,  where  it  is 
dumped  in  the  extensive  yards,  convenient  to  the  grinding-pens. 

The  coal  which  is  used  at  the  works  is  obtained  on  the 
property  from  the  coal  measures  above  the  clay.  It  is  mined 
from  a  vein  twenty-two  inches  thick,  and  is  brought  down  to 
the  head  of  the  tram-road  by  a  short  incline,  and  there  it  is  run 
in  with  the  clay,  and  trains  made  up  of  both  are  run  down  to 
the  brickyard. 

Not  all  fire-clay  works  would,  of  course,  require  such  ex- 
tensive facilities  for  handling  and  transporting  clay  as  are 
necessary  at  Mount  Savage,  Maryland,  but  wherever  it  is  pos- 
sible horse  and  mule  power  should  be  abandoned. 

As  steam  has  taken  the  heavy  work  of  transporting  the  pro- 
ducts of  the  country  from  the  horses  which  formerly  did  the 
overland  hauling,  so  it  is  doing  now  m  the  brick  factories. 

The  apparatus  for  drawing  the  clay  into  the  factory  by  the 
engine  being  in  the  first  place  cheaper  than  horses  and  carts, 
and  doing  the  work  without  a  driver,  besides  not  being  at  ex- 
pense when  idle,  it  was  a  natural  result  that  the  winding  drum 
and  automatic  dump-cars  were  adopted  by  all  enterprising 
brick  manufacturers. 

To  suit  different  demands,  manufacturers  of  brick-making 
machinery  usually  construct  two  sizes  of  winding-drums  and 
dump-cars,  which  are  self-contained  in  substantial  iron  frames 
and  which  can  be  operated  by  a  cord  from  the  clay-pit  or  by 
the  engineer  from  any  point  in  the  factory. 

The  frames  of  these  machines  are  so  constructed  that  they 
can  be  bolted  to  the  upper  part  of  the  track  timber,  which  does 
away  with  extra  framing  for  that  size.  The  pulley  on  No.  I 
machine  is  36x8  inches,  and  should  be  run  450  revolutions  per 
minute. 


360  BRICK,  TILES   AND   TERRA-COTTA. 

Weight  of  No.  I,  with  400  feet  of  iron  cable,  1300  pounds. 

The  manufacturers  commonly  build  two  standard  sizes  of 
dump-cars  of  good  heavy  timber,  well  ironed,  and  arranged  to 
dump  automatically  when  desired. 

No.  I  dump-car  holds  I  J^  cubic  yards  of  clay,  while  No.  2 
has  a  capacity  of  but  one  yard  of  clay ;  light  wrought-iron  T 
rails  are  employed  for  the  cars  to  run  on,  the  width  of  track 
between  centres  of  rails  being  forty  inches. 

The  bottom  of  the  dump  car  is  usually  in  two  parts,  hanging 
on  chains  which  are  attached  to  a  bell-crank,  which  is  keyed  to 
a  steel  cross-shaft  that  has  a  lever  on  the  outside  of  the  car, 
which  is  held  in  position  by  a  catch  that  hangs  down  between 
the  wheels  near  the  track.  A  stop  fastened  to  the  track  re- 
leases this  catch  and  lets  the  bottom  drop,  when  the  car  runs 
back,  and  the  diggers  by  a  pull  of  the  lever  again  place  the  bot- 
tom in  position.  This  is  done  very  quickly.  Side  dump-cars, 
arranged  to  dump  on  one  or  both  sides,  are  also  built  to  suit  dif- 
ferent localities,  by  The  Frey-Sheckler  Co.,  Bucyrus,  O. 

FIRE-BRICK    MANUFACTURE 

See  FIRE-CLAYS,  under  head  of  CLAY  in  Chapter  II.  The 
details  of  manufacture  and  the  equipment  of  plants  for  the  pro- 
duction of  fire-brick  vary  with  circumstances  and  the  kind  and 
variety  of  brick  to  be  made,  which  may  range  from  the  smallest 
nine-inch  shape,  weighing  three  pounds,  to  the  largest  glass- 
house shapes,  weighing  3,500  pounds  or  more. 

The  manufacture  of  fire-brick,  from  the  mining  of  the  crude 
clay  to  the  delivery  of  the  finished  goods  from  the  kiln,  is  a 
succession  of  processes  simple  enough  in  themselves,  and  easy 
enough  to  those  who  are  thoroughly  skilled  in  the  trade,  yet 
involving  great  care  and  incessant  vigilance  in  order  to  insure 
continued  success. 

Both  a  practical  and  theoretical  knowledge  of  the  business  is 
highly  desirable,  if  not  absolutely  necessary,  in  the  person  who 
assumes  the  active  management,  be  he  proprietor  or  hired 
manager.  By  practical  knowledge  is  not  meant  that  he  should 


THE   MANUFACTURE   OF   FIRE-BRICK.  361 

have  the  physical  ability  to  go  and  take  a  moulder's  or  presser's 
or  setter's  place  and  do  a  day's  work.  But  a  man  in  this  posi- 
tion should  be  so  practical  as  to  be  able  to  tell  at  a  glance 
whether  a  brick  or  piece  of  shape-work  is  made  properly  or 
not,  and  if  not,  what  is  the  matter  with  it.  He  should  be  able 
to  tell  as  soon  as  he  feels  of  the  tempered  clay  whether  it  is  too 
soft  for  the  work  for  which  it  is  being  used,  whether  the  kiln 
men  are  setting  the  brick  and  shapes  to  the  best  advantage, 
whether  the  firemen  are  firing  a  kiln  right  or  only  putting  in 
the  time,  whether  a  kiln  has  heat  enough  or  needs  to  go  twelve 
hours  longer.  He  should  be  able  to  tell  when  he  comes  into 
the  works  by  the  sound  of  the  machinery  whether  it  is  running 
all  right  or  not.  These,  and  a  hundred  other  things,  to  the 
''practical"  manager  should  come  as  natural  as  life.  If  the 
works  are  of  any  extent,  so  that  he  has  a  foreman  und.er  him, 
he  may  not  have  to  notice  some  of  these  things  once  a  month, 
or  longer,  but  he  should  possess  the  knowledge,  and  when  least 
expected  it  will  serve  him  in  good  stead.  He  may  or  may  not 
be  able  to  handle  men  to  advantage ;  if  not,  he  will  see  to  it 
that  he  gets  a  foreman  who  has  the  knack  of  doing  so,  for  it  is 
a  gift  all  men  do  not  possess.  Theoretical  knowledge  means  a 
great  deal  more  than  might  at  first  thought  be  supposed.  If  a 
man  as  manager  or  general  superintendent  is  ambitious  of  at- 
taining the  highest  results  he  needs  to  become  acquainted  with 
the  following  branches  of  science:  Chemistry,  geology,  mining, 
mineralogy,  metallurgy  and  mathematics.  Chemistry  will  teach 
him  the  composition  of  clays,  the  specific  influence  for  good  or 
evil  of  one  element  upon  another,  the  correct  selection  and 
mixing  of  clays  to  make  fire-brick  suited  to  different  uses. 
Geology  will  teach  him  all  that  can  be  known  of  the  formation 
and  origin  of  clay  beds,  and  also  where  to  prospect  for  the  clay 
he  may  be  seeking,  according  to  the  different  formations. 
Mining  will  teach  him  how  the  clay  can  be  mined  profitably, 
economically  and  without  waste  of  clay  territory.  This  depart- 
ment, however,  is  often  taken  out  of  the  hands  of  the  manager 
of  the  works  and  given  in  charge  of  a  competent  mining 


362  BRICK,  TILES   AND   TERRA-COTTA. 

engineer,  especially  where,  as  in  many  cases,  the  miners  are  at 
some  distance  from  the  works.  Metallurgy  teaches  the  dif- 
ferent processes  used  for  extracting  metals  from  their  ores  and 
the  mode  of  manufacture  of  the  various  metals,  and  thus  shows 
the  requirements,  sometimes  special  and  extraordinary,  of  fire- 
brick for  use  in  different  processes,  with  the  effect  upon  them 
in  various  positions  and  at  different  temperatures.  Mathe- 
matics is  of  great  use  to  the  manager  in  calculating  the  sizes 
and  shrinkages  of  difficult  shapes. 

These  subjects  enter  into  the  theoretical  knowledge  which  a 
manager  does  well  to  have.  Some  are  of  less  importance  than 
others.  Chemistry  and  metallurgy  are  almost  invaluable,  show- 
ing as  they  do  on  the  one  hand  the  causes  which  tend  to  the 
destruction  of  the  brick  under  diverse  conditions,  and  on  the 
other  hand  how  to  make  brick  that  will  present  the  greatest 
resistance  to  destruction,  by  a  proper  selection  and  mixing  of 
clays.  Such  knowledge  will  save  a  man  from  many  costly 
mistakes  into  which  he  may  otherwise  fall. 

In  the  manufacture  of  fire-brick  the  correct  choice  of  the  raw 
materials  is  the  basis  of  success.  The  methods  of  working  vary 
in  different  countries.  But  as  the  refractory  clays  present  very 
dissimilar  properties,  and  these  dissimilarities  show  themselves 
in  various  grades  and  differences  in  quality,  a  factory  where  a 
great  variety  of  products  is  to  be  turned  out  should  not  be  re- 
stricted to  the  working  of  but  one  bed  of  clay.  A  free  and 
unrestricted  choice  of  material,  on  which  the  value  of  the  pro- 
duct is  necessarily  dependent,  must  always  be  considered  as  a 
special  advantage  in  locating  a  factory.  In  working  crude 
clays  it  is,  however,  almost  always  necessary  to  add  chamotte, 
or,  as  a  substitute  for  it,  old  fire-brick  and  fragments  of  worn- 
out  clay  vessels  (glass  pots  or  seggers,  crucibles,  muffles,  etc.), 
whereby  the  mass  gains  in  density,  resisting  capacity,  solidity, 
inalterability. 

Storing,  Weathering  and  Elutriating  Fire-Clay.  The  piles 
of  clay  from  which  the  selection  of  clays  for  mixing  is  made, 
usually  adjoin  the  works  as  closely  as  possible  on  the  side  next 


THE   MANUFACTURE    OF   FIRE-BRICK.  363 

to  the  grinding  machinery.  In  many  places  the  amount  kept 
on  hand  is  large,  amounting  to  7,000  or  10,000  tons.  There 
is  no  object  in  thus  storing  fire-clay,  unless  it  be  either  to  insure 
a  supply  for  some  time  in  advance  and  guard  against  transient 
interruptions,  or  to  allow  the  clay  to  slack  and  break  up  fine, 
thus  curtailing  part  of  the  mechanical  preparations  otherwise 
needed.  There  is  a  belief  largely  current  that  allowing  a  clay  to 
be  exposed  to  the  influences  of  the  weather  acts  advanta- 
geously in  ridding  it  of  impurities.  Though  it  cannot  be 
denied  that  under  certain  conditions  this  would  be  so,  yet  it  is 
equally  certain  that  these  influences  are  much  overrated.  The 
impurities  which  would  thus  escape  are  potash  and  soda,  from 
such  compouds  as  feldspar  and  mica;  yet  the  decomposition 
of  these  minerals  having  been  effected  by  weathering,  the 
mechanical  conditions  which  would  aid  in  the  escape  of  the 
impurities  are  seldom  found.  A  strong  slant  to  the  floor  of 
the  clay  pile,  so  that  water  would  drain  away  quickly  and  well 
after  raining,  and  only  a  thin  layer  of  clay  on  the  floor  so  that 
impurities  from  the  top  layers  might  not  lodge  in  the  bottom, 
would  favor  the  escape  of  impurities ;  but  the  exact  opposite  of 
both  these  conditions  as  a  rule  prevails.  Iron  sulphide  and 
carbonates  of  lime  and  magnesia  would  also  tend  to  decompose 
and  leave  the  clay,  but  their  action  would  be  very  gradual. 
But  the  mechanical  subdivision  of  the  clay  which  takes  place  is 
undoubtedly  advantageous ;  alternate  frost  and  heat  has  long 
been  reckoned  as  a  valuable  agent  in  increasing  the  plasticity 
of  hard  clays. 

Some  clays,  however,  are  naturally  highly  plastic,  a  condi- 
tion which  detracts  from  their  refractoriness,  and  as  weathering 
promotes  plasticity  it  does  not  improve  this  class  of  clays. 
Clays  of  the  non-plastic  type  and  those  that  are  very  hard 
when  freshly  mined  should  all  be  weathered  before  using.  It 
takes  off  that  rawness  noticeable  in  freshly-mined  clays  of  this 
class,  conduces  largely  to  an  increase  of  purity,  renders  the 
clay  much  better  to  temper  and  easier  to  work,  and  makes 
sounder,  better  brick.  It  also  facilitates  the  sorting  out  of  im- 


364  BRICK,  TILES   AND   TERRA-COTTA. 

pure  matters  that  have  escaped  the  miners,  and  also  makes  it 
easier  to  grind,  thus  reducing  the  wear  and  tear  and  increasing 
the  capacity  of  the  plant.  To  obtain  the  full  benefit  from 
weathering,  the  clay  should  be  kept  exposed  some  months 
ahead,  and  not  stored  in  large  heaps,  except  it  be  turned  over 
periodically,  or  much  of  the  benefit  will  be  lost.  In  storing  the 
clay  it  should  be  arranged  so  that  it  can  be  used  systematically 
and  in  order  of  its  age. 

A  more  effective  but  also  more  artificial  means  of  improving 
fire-clays  is  by  elutriation,  the  separation  of  heavier  and  coarser 
particles  of  iron  combinations,  sand,  quartz,  etc.,  being  best 
effected  thereby.  Besides,  the  elutriating  waste,  especially 
when  elutriation  is  preceded  by  an  organic  disintegrating  pro- 
cess, carries  away  the  alkalies  as  well  as  a  portion  of  the  silica 
in  soluble  form.  The  treatment  of  the  clays  with  acids  should 
be  entirely  rejected ;  therefore  the  only  practical  means  for  im- 
proving the  clays  which  can  be  recommended  are  weathering 
and  elutriating,  and  only  these  means  have  come  into  use  in 
manufacturing  on  a  large  scale. 

Calcining.  A  certain  portion  of  the  clay  used  in  the  manu- 
facture of  refractory  materials  is  calcined  and  converted  into 
"  chamotte"  or  cement.  With  some  clays  calcining  is  a  prime 
necessity.  These  clays  are  such  as  are  highly  plastic,  and  if 
made  into  brick  entirely  from  the  raw  clay,  form  a  dense,  close 
body,  predisposed  on  that  account  to  incipient  vitrification, 
and  will  not  stand  sudden  and  extreme  changes  of  temperature. 
By  using  from  one- third  to  one-half  of  calcined  clay  a  granular 
body  is  obtained,  and  the  defects  just  mentioned  are  overcome. 
From  this  necessary  method  with  plastic  clays,  the  practice  of 
calcining  has  also  become  quite  common  in  treating  the  flint 
or  non-plastic  clays. 

The  most  important  constituent  of  all  refractory  wares  is  the 
calcined  clay  or  "  chamotte."  This  will  not  shrink,  and  pos- 
sesses the  power  of  union  in  the  greatest  possible  degree. 
These  two  important  qualities  have  more  to  do  with  the  pro- 
duction of  fire-clay  goods,  regular  both  in  size  and  in  quality, 
than  any  other  features  in  the  material  or  process  employed. 


THE    MANUFACTURE   OF   FIRE-BRICK.  365 

Another  advantage  in  calcining  clay  is  that  it  enables  one  to 
throw  aside  any  material  in  which  there  are  impurities  that  may 
have  been  previously  overlooked,  since  these  are  much  more 
easily  seen  when  the  clay  has  been  burned.  The  proportion  of 
calcined  clay  or  "chamotte"  used  must,  of  course,  vary  with 
the  size  of  the  brick  or  tile,  and  the  particular  use  for  which  it 
is  intended. 

In  calcining  fire-clay,  the  raw  clay  as  it  comes  from  the 
mine  or  pit  is  used,  and  of  this  the  lumps  are  preferable  for  this 
purpose.  The  reason  for  this  is  that  the  small  or  fine  clay  is 
more  trouble  to  handle  and  to  burn.  The  lumps  can  be  more 
easily  placed  in  the  kiln  and  the  fire  can  get  a  draft  through 
between  them.  Of  course  a  certain  quantity  of  small  or  fire- 
clay can  be  used  along  with  the  lumps.  Two  points  here 
should  be  observed.  First,  it  should  be  dry  when  set,  or  it 
will  be  liable  to  fall  in  the  kiln  and  obstruct  the  draft.  Second, 
it  should  also  be  freshly  mined,  as,  if  exposed  to  the  weather 
too  long  it  falls  to  pieces  and  cannot  well  be  handled.  These 
remarks  are  intended  to  apply  more  particularly  to  the  clays  of 
the  coal  measures,  which  are  either  «on-plastic  or  plastic,  and 
which  come  out  of  the  mine  in  hard  blocks.  The  soft  plastic 
clays,  either  fire-clays  or  terra  cotta  clays,  that  can  be  dug  out 
of  the  bank  in  large  pieces  or  blocks,  must  be  dried  before 
being  burnt,  and  can  then  be  treated  in  the  same  way  as  just 
described. 

Some  manufacturers  of  refractory  materials  have  the  clay  in- 
tended for  calcining  cut  in  twelve-inch  lengths  as  it  emerges 
from  a  6x6  inch  hole  at  the  bottom  of  an  ordinary  pug-mill,  and 
then  set  these  crude  blocks  of  fire-clay  next  to  the  walls  and  in 
the  same  kilns  in  which  the  wares  are  fired.  These  rough 
blocks  thus  calcined  are,  on  removal  from  the  kiln,  broken  by  a 
six-stamp  mill,  and  afterwards  ground  to  three  or  more  degrees 
of  fineness  in  ordinary  grinding  mills. 

The  more  advanced  fire-brick  makers,  however,  have  separate 
calcining  kilns,  which  are  built  of  brick,  with  a  boiler-iron  shell, 
as  will  be  described.  These  kilns  in  large  works  are  com- 


366  BRICK,  TILES   AND   TERRA-COTTA. 

monly  15  feet  high  and  8  feet  in  diameter,  with  fire  holes  a  few 
feet  from  the  bottom.  The  top  is  dome-shaped,  with  a  chimney 
from  the  centre  having  a  damper  on  top.  The  clay  is  charged 
in  through  a  hole  near  the  top  of  the  dome,  and  is  drawn  out  at 
the  bottom  of  the  kiln  on  iron  plates,  through  two  drawing- 
doors,  one  on  each  side  of  the  kiln,  20  tons  being  the  daily 
product  of  one  kiln. 

"Lean"  Materials. — Very  few  clays  can  be  used  as  mined. 
They  must  be,  as  it  were,  suspended  in  some  infusible  material 
which  will  prevent,  as  far  as  possible,  the  mechanical  effects  of 
the  heat,  and  allow,  at  the  same  time,  of  a  certain  amount  of 
expansion  and  contraction,  while  preventing  both  in  too  great  a 
degree.  These  materials  are  generally  called  "  lean,"  that  is, 
they  do  not  make  a  paste  with  water,  and  require  some  binding 
material  to  keep  them  together.  They  are  usually  quartz-sand 
or  pulverized  quartz,  burnt  clay,  old  brick,  serpentine,  talc, 
graphite  in  powder,  and  not  infrequently  small  coke,  when  the 
ash  is  not  to  be  feared,  and  when  graphite  either  cannot  be  had 
or  cannot  be  used  on  account  of  its  high  price.  Some  fire-clays 
from  Spain  contain  this  "lean"  material,  which  comes  from  the 
decomposition  of  talc-shale  in  which  they  have  been  suspended 
by  nature,  but  this  is  a  rare  exception.  The  mixture  must  gen- 
erally be  made  artificially.  Of  all  these  substances  quartz-sand 
is  the  cheapest,  but  it  has  been  found  by  experience  that  round 
grains  of  sand  are  less  liable  to  become  thoroughly  incorpo- 
rated with  the  binding  material  than  the  angular  pieces  of 
crushed  quartz,  so  that  when  a  very  refractory  material  is  re- 
quired crushed  quartz  is  always  used.  As  the  clay  contracts 
and  quartz  expands,  a  mixture  may  be  made  which  will  not 
change  its  form ;  but  in  a  given  case  this  may  not  be  the  best 
mixture  for  a  special  use.  If  the  material  has  only  to  resist  a 
great  heat,  an  excess  of  quartz  is  preferable ;  but  if  it  must  also 
resist  the  corrosive  action  of  basic  slags,  clays  burnt  at  a  high 
heat,  graphite  or  coke,  can  be  used.  When  the  mixture  is 
made  in  the  place  where  it  is  to  be  used,  without  previous 
burning,  it  is  generally  made  of  one-fifth  plastic  clay  and 


THE   MANUFACTURE    OF   FIRE-BRICK.  367 

four-fifths  burned  clay  or  quartz,  or  one-fourth  lean  clay  and 
three-fourths  burned  clay  or  quartz.  This  is  done  to  avoid 
contraction. 

When  chamotte  is  used  (i.  e.,  fire-clay  previously  burnt  and 
comminuted)  the  material  for  the  chamotte  is  comminuted  by 
grinding,  and  consists  partially  of  clay  as  refractory  as  possible, 
especially  burnt  for  this  purpose,  and  of  worn-out  glass-pots  or 
seggars,  crucibles,  muffles,  and  other  waste  of  refractory  clay 
articles.  The  more  refractory  the  clay,  as  well  as  the  chamotte 
used,  the  more  refractory  the  brick  will  be. 

The  finer  the  grain  of  the  chamotte  the  more  of  it  may  be 
added  to  a  clay,  whereby  the  mass  gains  in  homogeneity  and 
strength,  but,  on  'the  other  hand,  loses  in  capability  of  bearing 
changes  in  temperature,  and  inversely,  the  coarser  the  grain  of 
the  chamotte,  the  better  the  composition  will  bear  rapid  changes 
in  temperature.  It  is  best  to  endeavor  to  unite  both  properties 
by  adding  to  the  quite  finely  ground  crude  clay  a  mixture  of 
finely  and  coarsely  ground  chamotte,  taking  a  somewhat  larger 
proportion  of  the  latter.  As  a  rule  the  coarse  grain  should  not 
exceed  one-quarter  inch  in  size. 

The  proportion  in  which  the  burnt  clay  or  the  substitute  for 
it  is  mixed  with  the  crude  clay  varies  according  to  the  degree 
of  fatness  or  cementing  capacity  of  the  latter.  If  the  cement- 
ing capacity  is  considerable,  for  instance,  about  10  to  12,  as  in 
Belgian  clay,  and  the  chamotte  is  sharply  burnt,  which  is  neces- 
sary for  the  production  of  good  brick,  I  part  of  crude  to  2  parts 
of  burnt  clay  is  used.  If,  however,  the  crude  clay  is  quite  mea- 
gre, and  possesses  but  little  cementing  capacity,  for  instance  only 
=  3  to  5,  the  addition  of  chamotte  must  be  considerably  smaller 
in  ojrder  to  obtain  a  mass  of  sufficient  plasticity  and  suitable  for 
transport,  and  the  proportion  may  be  reduced  even  to  I  :  I  — 
i.  e.,  i  part  of  burnt  clay  to  I  part  of  crude  clay.  If  the  rule 
to  use  the  most  refractory  clay  at  the  disposal  of  the  manufac- 
turer, as  chamotte,  is  to  be  considered  as  valid,  it  follows  that 
nearly  everywhere  the  fat  clays  should  be  used  for  the  crude 
portion  of  the  composition,  and  the  meagre  clays,  which  are 


368  BRICK,  TILES    AND   TERRA-COTTA. 

frequently  more  refractory  and  generally  burn  very  hard,  for 
the  burnt  portion,  since  the  refractoriness  of  the  entire  mass  is 
thus  increased  by  the  greater  addition  of  burnt  clay  required. 
Variations  from  this  rule  will,  however,  be  sometimes  neces- 
sary, according  to  the  different  pyrometrical  value  of  the  clays 
at  disposal. 

Mixing  Fire-Clays. — It  is  in  the  mixing  of  the  clays  used  in 
the  manufacture  of  refractory  materials  that  the  skill  of  one 
operator  over  another  is  manifested. 

Clays  which  are  to  be  used  in  the  manufacture  of  fire-brick 
and  other  refractory  materials,  after  being  stored  in  the  sheds, 
cleaned,  and  carefully  dried,  and  in  all  other  ways  properly 
prepared,  are  afterward  mixed  with  the  substances  with  which 
they  are  to  be  incorporated,  which  are  classified  by  numbers, 
varying  according  to  the  size  of  the  sieve-holes  through  which 
they  will  pass.  The  quantity  and  quality  of  the  mixture  will 
determine  the  refractory  nature  of  the  material  to  be  produced. 
A  friable  paste  with  large  grains,  and  quite  porous,  resists  a 
great  heat.  One  with  fine  grains,  close  and  compact,  splits  at 
a  high  heat,  especially  if  it  is  not  homogeneous.  The  manner 
in  which  the  mixture  is  made  also  influences  the  quality  of  the 
brick  quite  as  much  as  the  material.  In  some  works  in  Bel- 
gium, after  taking  all  the  ordinary  precautions  to  make  the 
mixture  perfect,  it  is  submitted  to  a  succession  of  shocks  con- 
tinued for  some  time,  until  it  is  found  by  experiment  that  the 
materials  are  perfectly  mixed.  It  has  been  found  by  long  ex- 
perience that  the  brick  so  made  keep  their  form  perfectly, 
while  others  made  of  exactly  the  same  mixture  in  the  ordinary 
way  contract.  The  quantity  and  size  of  the  mixture  depend 
upon  the  size  of  the  article  to  be  manufactured.  When  coarse 
grains  are  used,  greater  thickness  must  be  given  to  the  sides  of 
the  articles  if  they  are  hollow,  and  they  must  be  made  larger 
if  they  are  solid,  thus  giving  a  mechanicnl  cohesion  where  a 
chemical  one  is  wanting.  The  usual  quantities  of  the  mixture 
for  brick  are  three-fifths  to  two-thirds  of  the  substances  added 
to  two-fifths  to  one-third  of  the  clay,  these  quantities  being 


THE   MANUFACTURE   OF   FIRE-BRICK.  369 

determined  by  volume  and  not  by  weight.  When  coke-dust  is 
used  it  does  not  seem  to  have  any  decided  effect  beyond  one- 
tenth.  The  action  of  coke  or  graphite  is  to  decompose  the 
metallic  oxides  as  they  form,  and  thus  prevent  their  union  with 
the  material  of  the  crucible.  Coke  may  be  profitably  used  in 
the  place  of  graphite  when  the  ash  is  in  small  quantity,  free 
from  iron  and  highly  aluminous.  Beyond  2  to  3  per  cent,  of 
graphite  cannot  be  profitably  used,  as  it  weakens  the  article 
and  renders  it  liable  to  break.  The  mixture  which  gives  the 
very  best  results  for  small  articles  is,  however,  worthless  for 
large.  It  will  generally  be  found  that  the  pieces  which  crack 
up  and  down  in  drying  have  had  too  much  material  mixed 
with  the  clay,  and  those  which  crack  laterally  have  had  too 
much  clay. 

The  very  greatest  importance  is  attached  in  some  industries 
to  not  having  a  mixture  made  by  a  machine.  In  many  places 
even  to  this  day  the  inhuman  method  of  heel-treading  is  used, 
because  more  care  is  then  exercised,  or  because  smaller  quan- 
tities being  mixed  at  once,  better  results  are  obtained.  The 
more  the  operations  of  mixing  are  repeated  the  better  the 
material,  and  it  is  undoubtedly  true  that  with  mechanical 
means  such  a  homogeneous  paste  is  not  produced  as  can  be 
made  by  human  labor,  because  the  whole  object  of  the  machine 
is  to  operate  on  large  quantities  at  a  time. 

Every  mixture  has  its  own  peculiar  rate  of  expansion  and 
contraction.  This  expansion  not  only  takes  place  when  the 
brick  are  made,  but  if  when  used  they  are  submitted  to  a  higher 
degree  of  heat  they  expand  still  further,  and  contract  again  on 
cooling  to  such  an  extent  that  at  Dowlais,  Wales,  the  tie-rods  of 
the  steel  furnace  are  slackened  when  the  furnace  is  getting  into 
heat,  and  are  tightened  again  as  it  cools.  At  Crewe,  England, 
this  is  made  self-acting  by  means  of  springs.  At  Creusot  the 
furnace-casing  is  made  so  strong  as  to  resist  the  pressure,  so 
that  the  roof-arch  must  rise  and  fall,  to  allow  for  the  expansion 
and  contraction.  When  neutral  brick  must  be  had  for  any 
reason,  it  is  mixed  with  just  enough  clay  and  burned  brick  to 
24 


3/0  BRICK,  TILES   AND   TERRA-COTTA. 

make  it  keep  its  form,  and  such  a  brick  is  generally  less  fusible 
the  less  silica  it  contains. 

The  proportions  of  flint,  "  lean,"  calcined  and  plastic  clays 
which  shall  compose  the  brick  or  other  fire-clay  product  having 
been  determined,  the  materials  are  selected  from  the  pile ;  the 
mixture  of  so  much  of  each  factor  is  made  by  counting  the 
shovelfuls  with  which  the  charging  barrow  is  loaded.  As  a  rule 
no  closer  proportion  is  kept  anywhere  than  careful  shoveling 
will  make.  In  the  manufacture  of  silica  brick,  however,  the 
most  scrupulous  care  is  necessary,  and  it  is  the  practice  to 
carefully  weigh  the  constituents,  platform-scales  being  used 
upon  which  the  loaded  barrows  are  run. 

Washing.  The  barrow  being  loaded,  the  clay,  be  it  plastic 
or  non-plastic,  should  be  washed.  The  washing  is  accom- 
plished by  running  the  barrow  over  a  sink  or  drain  and  drench- 
ing from  a  hose  above.  The  barrow  being  perforated  on  the 
bottom  speedily  drains  dry  again.  This  treatment,  though  not 
thorough,  tends  to  free  the  clay  from  dust,  mud  and  dirt,  which 
stick  to  it  from  the  diggings.  The  best  method  of  washing  is 
at  the  excellent  works  of  the  Harbison  &  Walker  Co.,  Pitts- 
burg,  Pa.  Their  machine  consists  of  a  cylinder  revolving  in  a 
slightly  inclined  position  in  a  trough  of  water.  The  wall  of  the 
cylinder  is  made  of  coarse  iron  gauze  or  netting,  and  on  the 
inside  is  bolted  a  spiral  flange  beginning  on  the  upper  end  and 
running  to  the  other  extreme.  A  charge  of  clay  is  introduced 
into  a  hopper  at  the  upper  end,  and  by  the  flange  is  slowly 
carried  down  the  length  of  the  cylinder,  being  agitated  in 
water,  which  is  about  six  inches  deep  in  the  lower  part  of  the 
cylinder.  This  machine  is  only  used  to  wash  hard,  uncalcined 
clays,  for  the  plastic  grades  would  not  stand  so  severe  a  treat- 
ment, and  calcined  clays  do  not  need  it.  Washing  is  only 
useful  or  advisable  where  the  hard  clays  in  use  are  mined  by 
benching  or  stripping  and  come  to  the  works  covered  with 
mud  or  dirt. 

Grinding  and  Tempering.  We  may  now  follow  the  clay 
through  the  successive  steps  of  grinding,  tempering,  molding, 
pressing,  drying  and  burning. 


THE   MANUFACTURE   OF   FIRE-BRICK.  371 

The  correct  mixtures  of  the  constituents  of  fire-brick  having 
been  accomplished,  it  is  necessary  in  the  further  working  of  the 
mass,  when  moistened  in  the  proper  proportion  with  water,  to 
be  especially  careful  to  obtain  complete  homogeneity  in  the 
interior  of  the  brick,  and  the  utmost  mechanical  strength. 
This  is  attained  by  a  thorough  and  intimate  kneading  of  the 
mass,  by  firmly  pressing  it  into  the  moulds  and  by  slowly  dry- 
ing the  moulded  brick.  By  over-hastening  the  drying  the 
mass  is  again  loosened,  which  injures  the  quality  of  the  brick 
as  regards  mechanical  strength. 

For  most  uses  in  practice  a  high  degree  of  mechanical 
strength  is  demanded  from  fire-brick,  which  depend  for  their 
refractoriness  upon  the  nature  of  the  clay  used  in  their  manu- 
facture. With  comparatively  less  refractory  clays  showing  an 
inclination  towards  slagging  at  a  not  very  high  degree  of  heat, 
the  ordinary  burning,  which  is  the  final  operation  of  manufac- 
ture, frequently  corrects  any  carelessness  committed  in  working 
the  mass,  the  brick  after  burning  appearing  sufficiently  strong 
and  hard.  With  very  refractory  clays  this  is,  however,  not.the 
case,  since  they  do  not  readily  slag  in  the  heat  of  an  ordinary 
kiln.  For  these,  sharp  burning,  which  is  absolutely  necessary, 
must  be  preceded  by  the  most  careful  and  thorough  working 
of  the  mass,  and,  if  possible,  a  strong  pressing  of  the  brick 
moulded  by  hand. 

The  grinding  of  the  clay  has  been  attempted  by  various 
methods,  including  crushing-rolls,  pulverizers  and  disintegrators 
of  various  kinds,  and  by  other  mechanical  appliances.  For 
hard  clays  none  of  these  have  proved  successful,  and  the  only 
method  to  give  satisfaction  is  the  grinding-pan,  either  wet-pan, 
dry-pan,  spiral  pug  or  chaser-mill.  The  latter  is  not  much 
used  now  for  grinding  clay  for  fire-brick  making,  although  it  is  a 
very  suitable  machine  for  some  other  branches  of  clay-working. 
The  method  of  preparing  the  clay  depends  largely  on  the  mode 
of  manufacture  adopted.  Up  to  the  present  time  the  moulding 
of  fire-brick  is  almost  entirely  accomplished  by  the  hand- 
method,  which  requires  the  clay  to  be  tempered  and  made  up 
quite  soft. 


3/2  BRICK,  TILES   AND   TERRA-COTTA. 

There  are  three  distinct  methods  of  accomplishing  this,  viz. : 
The  wet-pan  process,  the  dry  and  wet-pan  combined,  and  the 
dry-pan  and  pug-mill  combined.  The  methods  of  grinding 
and  tempering  are  somewhat  various.  The  "Fire  Brick  Mill," 
as  used  in  England,  is  unknown  in  the  United  States. 

The  methods  in  use  in  America  are  the  wet-pan  process, 
where  the  grinding  and  tempering  are  done  together  in  a  solid 
bottom  pan ;  the  dry-pan  and  wet-pan  combined ;  and  the  dry- 
pan  and  pug-mill  combined.  Other  methods  of  grinding,  such 
as  the  "ring-pit,"  for  example,  have  from  time  to  time  been 
tried,  but  have  failed  of  adoption  to  any  extent. 

The  wet-pan  is  found  in  most  common  use  where  a  hard, 
flinty  clay  and  considerable  calcine  are  used.  In  charges  con- 
taining considerable  amounts  of  both  these  bodies  and  only  a 
little  plastic  clay,  such  hard  and  intimate  mixing  is  the  only 
way  in  which  the  structure  of  the  brick  can  be  made  sound. 
This  wet-pan  process  is  used  entirely  in  the  Sciotoville  district, 
Ironton  and  Logan,  Ohio.  The  clay  is  dumped  into  the  pan 
in  the  rough,  water  is  turned  on,  and  the  charging  is  ground 
and  tempered  until  the  attendant  judges  it  to  be  fine  enough. 
There  are  some  objections  to  this  method  of  preparing  fire- 
clay, as  it  is  next  to  impossible  to  get  the  clay  of  a  uniform 
grain,  as  some  of  it  is  ground  too  fine,  while  another  portion 
may  be  too  coarse.  Then,  again,  the  process  is  slow,  and  for 
an  extensive  works  a  great  many  pans  are  required  to  prepare 
enough  clay,  the  usual  quantity  for  each  pan  being  a  day's 
work  for  one  moulder,  which  consists  of  4,000  brick,  with  a  few 
extra  thrown  in  for  waste.  The  pan  is  usually  fitted  with  a 
pipe  from  the  engine,  from  which  water  can  be  had  by  turning 
a  faucet.  Either  hot  or  cold  water  may  be  used  ;  it  probably 
makes  no  difference  which,  in  the  quality  of  the  brick,  but  the 
former  makes  the  work  of  the  moulder  much  more  endurable. 

The  wet-pan  method  has  one  great  advantage  which  is  not 
possessed  by  either  of  the  other  processes,  and  that  is  that  each 
moulder  may  be  on  a  different  grade  of  brick,  requiring  a 
different  mixture  of  clay ;  and  by  having  a  wet-pan  to  serve 


THE   MANUFACTURE    OF    FIRE-BRICK.  373 

each  moulder,  several  different  mixtures  can  be  in  preparation 
at  the  same  time,  whereas  in  either  of  the  other  processes  only 
one  kind  can  be  made  at  once,  and,  therefore,  all  the  moulders 
must  work  on  the  same  grade  of  brick. 

In  the  dry  and  wet-pan  combined,  the  tempering  is  done  in  a 
wet-pan. 

As  the  clay  has  been  already  ground  by  the  dry-pan,  a  few 
revolutions  of  the  wet-pan  are  sufficient  to  mix  the  clay  with 
water  and  bring  it  to  a  proper  temper  for  moulding.  The  clay 
is  usually  taken  out  by  hand,  either  with  a  loose,  ordinary 
spade  or  shovel,  or  by  a  level-shovel  fixed  for  the  purpose.  A 
special  style  of  pan  is  used  by  the  Union  Mining  Co.  of 
Mount  Savage,  Md.  In  this  pan  the  rim  is  loose  and  does 
not  revolve.  In  the  rim  is  a  gate  which  opens  into  the 
pan.  When  a  charging  of  clay  is  put  into  the  pan  and  is  suffi- 
ciently tempered,  the  gate  referred  to  is  opened  and  the  clay  is 
automatically  discharged,  and  the  pan  is  then  ready  for  another 
charging  of  clay.  This  is  an  ingenious  plan  and  a  great  im- 
provement upon  the  ordinary  pan.  The  clay  after  being  pre- 
pared is  carried  to  the  tables  of  the  various  moulders  by  an 
endless  belt,  where  the  brick  are  to  be  moulded  by  hand. 

The  dry-pan  and  pug-mill  mixer  combined  is  the  style  of 
grinding  and  preparing  fire-clay  least  adapted  to  general  use  of 
all  three  ways,  but  is  a  cheap  and  useful  method  in  some  cases. 
The  pan  is  very  similar  to  the  ordinary  wet-pan,  but  has  this 
difference :  the  floor  is  fitted  with  plates  cast  in  segments  fit- 
ting on  a  framework  of  radii  beneath  the  pan.  The  plates  are 
thus  fitted  into  a  level  and  continuous  floor;  they  are  full  of 
parallel  slots  or  holes,  which  open  immediately  into  a  larger 
room  from  the  underside,  so  that  any  particle  of  matter  which 
passes  the  surface  will  have  no  chance  to  stick  lower  down. 
Beneath  the  pan  is  a  bin  into  which  the  clay,  as  fast  as  it  is  re- 
duced fine  enough  to  pass  the  bottom  of  the  pan,  falls ;  in  this 
bin  revolve  arms,  which  collect  continually  the  powder  and  de- 
liver it  at  the  foot  of  an  elevating-belt  which  is  at  one  corner  of 
the  bin.  The  charge  is  all  introduced  together  and  is  run  until 


374  BRICK,  TILES   AND   TERRA-COTTA. 

it  has  all  disappeared  beneath  the  surface,  or  else  its  propor- 
tion of  calcine  would  not  be  equally  distributed.  All  dry  pans 
are  subjected  to  this  disadvantage,  that  the  softest  parts  go 
through  first  and  the  harder  last,  so  that  the  powdered  clay  as 
delivered  by  the  elevating-belt  would  not  be  strictly  homo- 
geneous ;  also,  the  largest  part  of  the  clay  goes  through  at 
once,  and  the  longest  part  of  the  grind  is  devoted  to  getting 
the  least  of  the  charge  through,  which  is  a  waste  of  energy. 
Another  disadvantage  resulting  from  this  plan  is  the  fact  that 
the  hard  material  is  never  rendered  finer  than  is  necessary  to 
pass  the  holes  in  the  floor,  which  to  make  the  machine  work  at 
all  rapidly  are  necessarily  larger  than  is  good  for  the  brick. 
The  powdered  clay  having  been  delivered  into  a  bin  above,  is 
ready  to  be  mixed  as  needed.  The  mixing-machine  is  a  trough 
about  eighteen  inches  wide  by  eight  feet  long  by  eighteen 
inches  deep ;  in  it  works  a  horizontal  axis  on  which  are  fixed 
cutting-arms,  which  are  arranged  spirally,  but  at  such  a  pitch 
that  their  action  is  slow  in  moving  the  clay  forward.  The  tem- 
pering is  done  by  merely  adding  clay  and  water,  and  allowing 
the  machine  to  mix  it  up  to  a  paste. 

In  the  case  of  plastic  clays,  an  open  mill  or  mixer  may  be 
used,  but  for  non-plastic  clays,  or  where  considerable  calcine  is 
used ;  it  must  be  a  closed  pug-mill  of  good  length  in  order  to 
get  the  clay  sufficiently  tempered  for  moulding. 

A  process  of  grinding  and  tempering  fire-clay  which  is  much 
in  favor  in  the  older  river  works  of  Jefferson  county,  Ohio,  and 
also  at  Mineral  Point  and  Haydenville,  Ohio,  is  theoretically 
the  most  correct  of  all  methods  in  use ;  but  it  is  also  the  most 
expensive  as  well.  Along  the  river  the  clays  used  are  as  hard 
and  rocky  as  sandstone  when  they  are  newly  mined ;  they  are 
sandy  and  apparently  non-plastic,  but  by  this  treatment  they 
develop  into  one  of  the  best  working  clays  in  the  State  of  Ohio. 

The  dry-pan  used  is  of  the  kind  previously  described,  and  is 
adjusted  to  deliver  the  ground  clay  into  an  elevator.  This 
carries  it  up  to  the  top  of  the  building  and  delivers  it  upon  a 
screen.  This  screen  is  a  box  about  fourteen  feet  long,  by  four 


THE    MANUFACTURE   OF   FIRE-BRICK.  375 

feet  wide,  by  seven  feet  deep ;  the  bottom  of  this  box  is  made 
of  sheets  of  perforated  sheet-iron,  the  holes  about  one-tenth  of 
an  inch  in  diameter;  the  slant  is  about  45  degrees,  so  that 
whatever  enters  the  screen  is  sure  to  leave  it  either  by  passing 
through  or  by  running  off  at  the  end.  That  which  escapes 
from  the  end  is  carried  down  by  spouts  to  the  dry-pan,  and  is 
re-ground,  so  that  a  charge  being  introduced  runs  on  until  it  is 
all  through  the  sieve.  That  which  passes  the  sieve  is  caught 
by  a  cloth  or  board  hopper  beneath,  and  is  conducted  to  the 
tempering  mill  or  to  the  bins  for  storing.  The  clay  which  has 
been  screened  is  beautifully  fine  and  even.  The  tempering 
mill  is  on  the  same  principle  as  the  wet-pan  first  described,  but 
is  of  a  larger  diameter ;  the  rolls  are  frequently  arranged  to 
turn  instead  of  the  pan ;  they  are  of  larger  diameter  and  less 
thickness  than  the  wet-pan  rolls,  and  weigh  usually  1,800 
pounds  each.  The  pan  is  provided  with  water,  and  a  charge  is 
thrown  in  wet  and  ground  briskly  until  as  plastic  as  can  be ;  by 
this  course  of  treatment  the  qualities  of  the  clay  are  developed 
to  the  best  possible  effect. 

Moulding  and  Pressing.  In  England  the  brick  are  all  made 
of  very  stiff  clay,  in  brass  moulds,  and  are  not  pressed.  They 
are  perfectly  solid  and  square,  and  in  fact  need  no  pressing. 
This  method  has  not  been  adopted  to  any  extent  in  the  United 
States.  The  almost  universal  method  employed  in  this  country 
is  to  make  the  brick  in  wooden  moulds,  using  very  soft  clay,  or 
"  mud,"  as  it  is  technically  termed  ;  then  to  spread  the  brick  on 
a  warm  or  hot  floor  to  stiffen,  and  then  press  in  a  hand  lever 
press,  and  return  to  the  hot  floor  to  finish  drying. 

The  object  of  pressing  is  not  so  much  to  make  the  brick 
dense  as  to  square  them  up  and  put  them  in  better  shape. 
This  method  of  moulding  fire-brick  is  followed  in  every  section 
of  the  country,  East,  West  and  South,  and  will  probably  con- 
tinue to  be  largely  made  in  this  manner  for  some  time  yet  to 
come.  In  some  of  the  older  works  the  brick  are  moulded  in 
iron  moulds,  the  clay  being  tempered  in  "ring  pits;"  a  day's 
work  in  such  plants  being  to  mould  and  press  1,200  brick,  the 


376  BRICK,  TILES   AND   TERRA-COTTA. 

men  wheeling  their  own  clay  from  the  pit  to  the  moulding- 
table  ;  a  gang  comprising  a  moulder,  presser  and  off-bearer. 
Hand-pressing  is  almost  the  universal  rule,  but  there  is  a  de- 
mand for  something  better.  This  is  now  at  hand  in  one  or  two 
steam-power  presses  that  are  powerful,  simple  and  easy  to 
operate,  and  which  effect  a  saving  of  at  least  half  of  the  cost  of 
hand-pressing.  At  the  same  time  it  is  often  claimed  that  there 
is  no  advantage  in  steam-pressing ;  that  hand-presses  can  be 
moved  about  to  suit  the  work,  and  are  handier,  etc.  There  is 
a  semblance  of  truth  in  much  of  this,  but  when  really  sifted 
down  there  is  very  little  in  it.  No  account  is  taken  of  the  time 
that  is  taken  up  in  moving  the  press  around,  nor  of  the  fact 
that  the  brick  have  to  be  moved  from  the  warm,  or  stiffening 
floor,  to  the  hot,  or  drying  floor  (of  which  more  anon),  and 
hence  but  little  more  moving  is  required  to  press  than  on  a 
stationary  steam  press,  and  with  the  different  system  that  can 
be  adopted,  the  saving  in  cost  is  as  above  stated. 

In  the  fire-brick  factories  of  St.  Louis,  Mo.,  there  is  in  use  a 
somewhat  different  method  from  the  above.  There  the  clay  or 
mud  is  made  very  stiff  and  moulded  direct  into  the  press-box 
of  a  press,  and  when  it  leaves  the  press  is  finished  ready  for 
drying.  Of  course  a  man  cannot  make  so  many  brick,  not 
over  about  half  the  quantity ;  but  the  saving  of  so  much  un- 
necessary handling,  and  the  saving  in  room  required,  make  a 
decided  reduction  in  the  cost  of  the  brick.  This,  of  course,  is 
confined  to  nine-inch  work,  or  at  most,  to  13^x6  furnace 
blocks.  All  large  shape  and  special  work  is  of  course  made  in 
wooden  moulds  by  hand,  and  the  writer  is  inclined  to  think  from 
practical  experience  that  there  is  hardly  likely  to  be  any  change 
in  the  method  of  making  this  class  of  work.  In  the  various 
forms  of  nine-inch  work,  however,  which  forms  the  staple  of  the 
fire-brick  business,  machinery  has  been  introduced  which  seems 
likely  to  effect  a  revolution  in  the  trade.  This  is  emphatically 
a  mechanical  age,  and  its  influence  has  long  been  felt  and  ac- 
knowledged by  every  other  department  of  clay  manufacture. 
Fire-brick  makers,  however,  have  been  content  to  still  go  on  in 


THE   MANUFACTURE    OF   FIRE-BRICK.  377 

the  old  humdrum  way,  and  the  moulder  laboriously  makes  his 
clot,  or  warp,  or  pone,  and  whacks  it  into  the  mould.  Fire- 
brick makers,  as  a  rule,  have  settled  down  to  the  idea  that  they 
will  never  be  made  any  other  way  as  long  as  the  world  stands, 
and  few  of  them  will  even  listen  to  the  idea  of  making  by 
machine.  In  fact,  there  has  always  been  a  decided  notion  that 
they  cannot  be  made  except  by  hand  moulding.  But  all  this 
is  no  argument,  and  it  should  not  be  forgotten  that  similar 
opinions  have  been  held  upon  many  other  things  in  regard  to 
the  adoption  of  machinery.  It  must  be  confessed  that  many 
failures  and  few  successes  have  attended  all  attempts  at 
machine-made  fire-brick  in  the  past.  But  every  failure,  if 
carefully  observed,  is  one  step  nearer  to  success. 

Mr.  Joseph  Cowen,  of  Newcastle,  England,  says  that  in  the 
North  of  England  (Northumberland  and  Durham)  attempts 
have  been  repeatedly  made  to  produce  fire-brick  by  machinery, 
yet  without  success ;  whereas  in  Wales  such  an  application  has 
succeeded,  owing,  it  is  suggested,  to  the  Welsh  clay  differing 
in  quality  from  that  of  the  North ;  and  in  his  opinion  fire-brick 
will  continue  to  be  made  by  hand.  >Machine-made  brick,  he 
says,  are  always  more  compact  than  those  made  in  the  old 
way,  and  this  he  considers  a  defect.  Mr.  Cowen  here  prob- 
ably strikes  the  keynote  to  the  cause  of  most  of  the  past  fail- 
ures in  previous  efforts  to  make  first-class  fire-brick  by 
machinery. 

The  question  of  moulding  without  pressing,  as  in  England, 
and  that  of  moulding  and  pressing,  as  practiced  in  this  country, 
is  worthy  of  consideration,  hence  the  writer  will  give  particulars 
of  the  English  process  and  reasons  why. 

The  clay  is  prepared  as  stiff  as  it  can  be  worked  up  by  the 
hand  of  the  moulder  into  a  solid  warp  or  ball  ready  for  the 
mould.  As  he  raises  it  from  the  table  it  will  be  found  to  be 
regular  in  form,  the  shape  of  the  mould,  only  smaller,  so  that 
it  will  go  in  quite  clear  and  spread  out  to  the  sides  and  ends  of 
the  mould.  The  moulder  raises  it  up  well  and  throws  it  into 
the  mould  quickly  and  with  force.  The  moulds  of  one  brick 


378  BRICK,  TILES    AND   TERRA-COTTA. 

each  are  cast  of  brass,  light  and  tbin,  with  stronger  flange 
round  the  wearing  parts,  that  is,  the  top  and  bottom.  The 
moulds  being  open,  between  these  two  flanges  light  oak  sides 
or  strips  are  placed,  running  about  two  inches  past  each  end, 
forming  lugs  for  the  off-bearers  to  handle  them.  These  ends 
are  rounded  off,  and  a  small  iron  bolt  is  riveted  through  each 
pair  of  ends,  making  the  whole  tight  and  firm.  The  moulder 
will,  after  delivering  the  clay  into  the  mould,  strike  off  any  sur- 
plus clay,  sprinkle  on  a  little  water,  then  again  run  his  striker 
or  planing  board  twice  over  the  surface,  giving  it  a  perfectly 
smooth  and  finished  appearance.  A  boy  then  takes  the  mould 
from  the  table  and  delivers  the  brick  on  a  pallet  which  is  placed 
on  a  small  bench  by  his  side.  The  second  boy  or  runner  comes 
up  to  the  bench  with  pallet  in  each  hand,  lays  one  on  the  bench 
and  places  the  other  on  top  of  the  brick,  picking  up  the  two 
pallets  with  the  brick  between,  which  at  the  same  time  presses 
down  any  bead  left  on  the  brick  in  coming  from  the  mould ;  he 
runs  off  with  it  and  places  it  on  edge,  the  same  as  when  taken 
from  the  press. 

The  mould  being  of  perfectly  smooth  brass  requires  neither 
sand,  water  nor  oil,  and  the  ball  of  clay  being  properly  pre- 
pared by  hand  and  well  thrown  in,  the  brick  comes  out  with  a 
perfectly  smooth  skin,  as  from  the  press. 

In  this  way  of  moulding  the  cost  is  exactly  the  same  as 
moulding  and  re-pressing  in  this  country.  In  the  former  a  man 
and  two  boys  mould  2,000  brick  for  a  day's  work,  in  the  latter 
a  man  and  two  boys  mould  2,000  and  press  them.  It  may  be 
asked,  Where,  then,  is  the  advantage?  It  is  in  the  uniformity 
of  the  density  of  the  body  and  the  perfect  regularity  in  thick- 
ness, a  matter  of  great  importance  in  fire-brick  manufacture 
and  a  regular  cause  of  complaint  where  brick  are  re-pressed. 
This  irregularity  of  thickness  in  re-pressing  is  principally  caused 
from  the  brick  when  moulded  and  placed  on  a  dry-floor  which  is 
hotter  in  some  places  than  in  others,  and  also  that  the  brick  last 
made  have  been  on  the  floor  longer  than  those  first  made  be- 
fore going  to  the  press.  Brick  to  be  regular  in  thickness  must 


THE   MANUFACTURE    OF   FIRE-BRICK.  3/9 

all  be  of  the  same  consistency  or  stiffness  when  they  are  placed 
in  the  press  box,  which  is  almost  an  impossibility ;  hence  the 
advantage  of  the  former  system. 

In  the  St.  Louis,  Mo.,  district  the  method  of  moulding  is  dif- 
ferent from  either  of  those  which  have  been  described.  There 
no  moulds  are  used.  The  clay  is  made  very  stiff  and  moulded 
in  the  press-box  of  a  hand-press  at  the  same  time,  and  put  out 
on  the  hot  floor  to  dry  without  any  immediate  stiffening. 

Concerning  the  method  of  making  fire-brick,  Mr.  Thomas 
Pickering,  of  Chicago,  111.,  recently  wrote  to  Mr.  Davis,  as  fol- 
lows :  "  Having  made  fire-brick  in  England  for  eighteen  years 
in  the  county  of  Durham  and  in  Northumberland,  near  New- 
castle-on-Tyne,  it  may  be  of  interest  to  you  to  give  the  methods 
of  fire-brick  making  in  those  two  counties.  I  will  confine  my 
remarks  simply  to  the  making. 

"The  clay  is  on  the  moulding  bench,  and  on  the  bench  is  a 
piece  of  flannel  about  twelve  inches  square  tacked  on  the  bench 
to  make  the  ball  on.  There  is  a  piece  of  wood  two  inches 
thick,  five  inches  wide  and  ten  inches  long,  covered  with  flannel 
stretched  as  tight  as  possible. 

"The  stamp  is  nailed  on  with  a  staple  driven  in  at  the  end  of 
a  piece  of  wood,  so  that  when  the  mould  is  put  on,  the  stamp 
will  be  right  in  the  center  of  the  brick. 

"The  mould  is  solid  brass  with  a  flange  on  the  top  side  of 
the  mould,  with  no  bottom.  The  mould  is  about  ten  pounds 
weight,  with  one  side  of  the  mould  a  little  lower  than  the  other, 
to  allow  for  a  little  sagging  when  the  brick  is  put  down  on 
edge.  The  mould  is  put  on  the  piece  of  wood  covered  with 
flannel. 

"  Then  the  ball  is  made  and  thrown  into  the  moulds,  the  sur- 
plus is  taken  off  with  the  hand.  Then  a  hardwood  streaker  is 
taken  to  smooth  it  off.  The  streak  is  then  thrown  into  a  little 
box  filled  with  water  in  front  of  the  moulder,  which  is  called 
the  streak-kit. 

"The  mould  is  emptied  onto  a  pallet  which  is  taken  away  by 
boys.  Each  moulder  has  two  boys  or  girls.  The  moulder 


380  BRICK,  TILES    AND    TERRA-COTTA. 

must  be  careful  to  have  the  short  side  of  the  mould  to  the  left 
hand,  so  that  when  the  boy  takes  the  brick  up  to  put  it  on  the 
floor  the'short  side  will  be  on  the  bottom. 

"  Circle  brick  and  cupola  brick  are  made  the  same  way,  and 
tiles  weighing  as  much  as  twenty-five  pounds.  The  moulds 
for  cupola  and  special  brick  are  made  of  wood  lined  with  plate 
zinc. 

"  Some  places  all  the  special  brick  weighing  over  twelve 
pounds  are  made  by  the  ton,  paying  from  elevenpence,  to 
thirteenpence  per  ton.  A  moulder  can  earn  from  six  to  seven 
shillings  per  day,  getting  two  shillings  per  thousand  for  brick. 
A  moulder  can  make  from  2,500  to  3,500  brick  in  a  day." 

Drying  and  Tempering.  The  paste  made,  and  the  article 
completed,  it  must  be  dried  or  "tempered."  This  for  cruci- 
bles, retorts,  etc.,  is  commenced  in  the  open  air,  and,  if  possi- 
ble, out  of  the  draft.  If  the  draft  cannot  be  excluded,  the  place 
where  the  drying  takes  place  is  slightly  heated,  commencing 
at  a  temperature  from  60°  to  70°  F.,  and  keeping  it  up  from 
twenty-five  to  thirty  days;  then  increasing  it  from  80°  to  100°, 
leaving  the  article  as  long  as  possible,  with  an  active  ventila- 
tion, but  the  same  temperature  being  kept  up.  The  article 
should  remain  in  a  temperature  of  from  150°  to  180°  for  at 
least  six  weeks.  Brick,  tile  and  blocks  do  not  require  so  much 
care;  but  crucibles  and  retorts  do.  Long  experience  has 
proved  that  there  is  a  great  economy  in  conducting  this  pro- 
cess of  tempering  as  slowly  as  possible,  and  that  it  influences 
materially  the  refractory  nature  of  the  article.  It  is  found  by 
actual  experiment  in  crucible  works  that  those  crucibles  made 
from  the  same  mixture,  tempered  during  six  to  eight  months, 
last  more  than  three  times  as  long  as  those  which  had  been 
tempered  only  two  ;  so  that,  in  general,  the  older  the  article 
before  being  burned  the  better.  This  desiccation,  while  per- 
haps it  is  the  most  important  part  of  this  manufacture,  is  un- 
doubtedly the  one  most  neglected.  A  poor  article  well  tem- 
pered is  often  better  than  the  best  which  has  been  hastily  dried. 
By  working  rapidly  and  filling  up  cracks  as  they  form  in  a 


THE    MANUFACTURE    OF   FIRE-BRICK.  381 

too-rapidly  heated  drying-house,  with  a  very  liquid  material,  in 
order  to  secure  complete  penetration,  both  time  and  money  are 
lost.  The  material  never  lasts  nearly  so  long  as  when  slowly 
dried.  In  the  works  at  Andenne,  in  Belgium,  large  pieces,  like 
glass-house  pots,  are  kept  six  months  in  the  drying-house  be- 
fore they  are  used,  and  during  this  time  the  greatest  care  is 
taken  to  prevent  drafts,  so  that  no  air  colder  than  the  drying- 
room  shall  strike  them.  Leaving  the  door  of  the  drying- 
furnace  open  has  been  known  to  crack  the  pieces,  which  had 
been  up  to  this  point  most  carefully  prepared  and  tempered. 

The  drying  of  fire-brick  in  the  United  States  is  done  chiefly 
on  fire-heated  floors,  but  it  is  gratifying  to  note  that  floors 
heated  by  exhaust  steam  from  the  engine  are  at  last  coming  to 
have  their  advantages  recognized,  as  their  construction  and 
operation  become  better  understood.  These  floors  have  been 
successfully  used  in  England  for  many  years.  Both  forms  of 
dry-floors  will  be  found  fully  described  above.  For  large  works 
there  is  no  reason  why  the  superior  economy  of  tunnel-dryers 
should  not  be  made  available  for  drying  the  brick  after  being 
pressed. 

The  drying  and  tempering  of  all  classes  of  refractory  mater- 
ials is  an  important  part  of  the  manufacture — the  more  care- 
fully the  drying  of  the  clay-wares  is  conducted  the  more 
satisfactory  and  valuable  will  be  the  product.  A  poor  article 
well  tempered  is  often  more  satisfactory  than  a  better  grade  of 
ware  would  be  if  too  hastily  dried.  If  there  be  no  overheating 
of  the  brick  on  the  dry-floor,  there  will  result  no  cracking  of 
them. 

There  should  be  no  unnecessary  handling  of  the  green  brick, 
and  every  precaution  should  be  taken  to  avoid  the  chipping 
and  other  injuries  which  the  brick  have  inflicted  upon  them 
before  they  are  fired.  The  best  way  to  obtain  a  high  grade  of 
fire-brick  is  to  put  them  on  a  mildly  warm  floor  and  allow  them 
to  stiffen  gradually  through  and  through,  so  as  to  be  in.  good 
condition  for  pressing  the  morning  following  the  day  during 
which  they  were  moulded.  After  being  pressed  the  brick  can 


382  BRICK,  TILES   AND   TERRA-COTTA. 

then  be  placed  on  a  hot  floor  and  dried,  care  being  exercised 
to  let  none  but  thoroughly  dry  brick  go  to  the  kiln.  These 
precautions  insure  the  production  of  sound  and  well-finished 
brick.  In  some  fire-brick  works  the  brick  are  taken  from  the 
moulder's  bench  and  placed  upon  a  floor  which  is  much  too 
hot,  and  from  which  in  a  few  hours  they  are  picked  up  and 
pressed  and  put  down  again  to  finish  drying.  The  conse- 
quence of  this  method  is  that  the  brick  are  pressed  Before  the 
middle  of  the  brick  is  sufficiently  dry — the  outside  and  edges 
are  hard  enough,  no  doubt,  for  pressing,  but  the  centres  of  the 
brick  are  much  too  soft  for  the  application  of  pressure.  Good 
fire-brick  cannot  be  made  after  this  mode.  The  custom  is  to 
keep  the  floors  hot  constantly ;  the  mass  of  the  body  heated 
makes  this  easy  to  be  done.  The  fuel  used  is  coal  slack  in 
almost  all  cases,  as  its  combustion  is  gradual,  and  after  the  floor 
is  once  hot,  gradual  heat  is  the  kind  wanted.  Brick  placed  on 
such  a  floor  dry  in  twenty-four  hours  from  the  tempered,  plastic 
clay  to  a  state  so  hard  that  the  hand  can  make  no  impression 
on  them.  Lack  of  drying-floor  constitutes  one  of  the  greatest 
obstacles  to  an  increase  of  capacity  of  a  factory.  Air-drying 
is  usually  done  in  the  second  story  over  the  ordinary  drying- 
floor.  If  the  roof  be  tight  the  heat  in  the  second  story  is  quite 
uniform,  and  is  strong  enough  to  do  quite  rapid  work.  The 
temperature  is  often  100°  or  120°  naturally,  and  by  using  a 
slat-work  floor  the  capacity  is  largely  increased.  The  kinds  of 
ware  adapted  to  air-drying  are  large  pieces  which  the  heat 
of  a  floor  can  only  attack  on  one  side  at  a  time,  which  is  always 
done  at  a  risk  of  cracking. 

In  the  manufacture  of  fire-brick  on  a  large  scale  by  the  soft- 
mud  process,  when  many  thousand  brick  are  moulded  in  a  day, 
it  is,  of  course,  necessary  to  have  some  expeditious  method  of 
drying,  and  the  rule  in  such  works  is  to  have  the  brick  dry  and 
in  the  kiln  within  twenty-four  hours  of  the  time  when  they  were 
moulded.  Although -any  suggestion  that  a  longer  time  than 
this  should  be  allowed  the  brick  is  scarcely  practical,  yet  the 
fact  cannot  be  controverted  that  the  refractory  qualities  of  all 


THE   MANUFACTURE   OF   FIRE-BRICK.  383 

classes  of  fire-clay  wares  are  much  improved  by  slow  drying 
and  long  tempering  in  the  dry-house.  The  various  tunnel - 
dryers  now  on  the  market  are  well  adapted  to  the  drying  of 
fire-brick  in  large  quantities.  After  the  brick  have  been  made 
and  dried  they  are  wheeled  into  the  kiln  and  set  for  burning. 

Burning.  The  manner  of  setting  the  brick  in  the  kilns  de- 
pends upon  so  many  circumstances  that  no  general  rule  can  be 
made  for 'this  part  of  the  work.  In  kilns  which  are  gas-fired 
the  manner  of  setting  is  different  from  the  way  in  which  the 
brick  are  set  for  burning  in  coal-fired  kilns.  Special  instruc- 
tions on  this  point  are  always  furnished  by  the  builders  of  gas- 
fired  kilns. 

On  the  subject  of  setting  and  burning  fire-brick  and  the 
construction  and  operation  of  fire-brick  kilns  a  large  volume 
could  be  written. 

The  Harbison  &  Walker  Co.,  of"*  Pittsburgh,  Pa.,  use  the 
Dunnachie  gas-fired  kiln,  for  which  Charles  T.  Davis,  of  Wash- 
ington, D.  C.,  is  the  agent  in  the  United  States.  For  a  descrip- 
tion of  the  kiln  see  Chapter  IX. 

The  most  appropriate  form  of  kiln  suited  to  individual  re- 
quirements must  be  determined  by  local  circumstances,  cost  of 
fuel,  labor,  etc.  Gas- fired  kilns,  however,  are  more  economical 
to  operate  in  both  fuel  and  labor  cost  than  are  coal-fired  kilns, 
and  on  these  accounts  are  being  adopted  by  the  leading  fire- 
brick manufacturers  of  this  country  and  Europe. 

Fire-brick  require  to  be  thoroughly  burned,  and  if  they  pos- 
sess any  refractory  qualities,  a  high  temperature  is  necessary 
to  accomplish  this,  in  order  to  bring  them  to  the  point  where 
the  -shrinkage  or  contraction  shall  have  ceased.  When  taken 
out  of  the  kilns,  if  not  shipped  away  immediately,  the  brick 
should  be  stored  in  a  good  water-tight  stock-shed,  as  brick  and 
other  refractory  products  should,  if  it  is  possible  to  avoid  it, 
never  be  allowed  to  get  wet. 

In  order  to  acquire  and  hold  a  desirable  trade- demand  for 
refractory  materials,  only  first-class  wares  should  be  placed 
upon  the  market.  In  order  to  do  this  it  is  necessary  to  place 


384  BRICK,  TILES    AND    TERRA-COTTA. 

in  charge  of  fire-brick  works  only  experienced  and  careful  fire- 
brick makers — men  who  will  give  their  personal  attention  to  all 
the  details  in  the  different  processes  of  .mixing  the  clays  and 
the  moulding  and  burning  of  the  brick.  The  fire-brick  having 
been  made  and  burned,  it  is  the  duty  of  the  manufacturer  not 
to  allow  the  brick  to  become  exposed  to  the  weather,  and 
shipped  away  full  of  moisture,  as  it  is  expected  that  all  fire- 
brick shall  go  to  the  furnaces  for  use,  free  from  moisture. 

CALCINE    KILN. 

The  quantity  of  "  chamotte  "  or  calcine  required  in  a  fire- 
brick works  depends  largely  on  the  nature  of  the  clay  in  use 
and  the  proportion  of  tiles  and  blocks  made.  If  the  supply  of 
calcine  required  is  of  a  limited  character,  lumps  of  raw  clay 
may  be  placed  in  each  kiln ;  but  in  cases  where  more  calcine  is 
necessary  than  this  method  will  supply,  it  is  advisable  to  make 
provision  for  the  demand  by  the  erection  of  a  calcine  kiln. 
This  form  of  kiln  is  simple  in  construction,  being  erected  some- 
what after  the  plan  of  a  lime-kiln,  and  worked  in  a  similar 
manner;  that  is,  the  kiln  is  always  kept  filled.  When  the 
calcine  at  the  bottom  of  the  kiln  is  sufficiently  burned,  it  is 
drawn  out,  the  remainder  settling  down,  leaving  a  vacancy  at 
the  top,  which  is  filled  with  a  further  supply  of  lump  clay,  so 
that  the  calcining  process  is  one  of  regular  feeding  and  draw- 
ing out  of  the  clay.  In  Figs.  127,  128  and  129  is  shown  a 
calcine  kiln.  The  kiln  is  5  feet  in  diameter,  and  15  feet  from 
the  bottom  to  the  cone  or  stack.  The  base  has  four  fire-holes 
1 8  inches  wide,  and  fitted  with  3-feet  grates.  Letters  d  and  c 
represent  the  feeding  and  discharge  doors,  the  clay  being  con- 
verted into  calcine  as  it  gradually  descends  from  the  height  of 
the  door  d  to  the  door  c. 

The  calcine  kiln  should  be  built  as  near  the  mill-room  as 
possible,  and  connected  with  the  clay  bank  by  a  trestle  at  a 
line  level  with  the  feeding  door  d,  so  that  the  loaded  cars  may 
be  run  directly  up  to  the  door.  Where  there  is  no  accommo- 
dation for  thus  conveying  the  clay  to  the  calcine  kiln,  a  hoist  or 


THE   MANUFACTURE   OF   FIRE-BRICK. 


385 


inclined  plane  would  be  necessary.     The  kiln   being   in  close 
proximity  to  the  machinery,  this  could  be  done  at  small  expense. 

FIG.  127. 


GROUND  PLAN  OF  BASE,  INCLUDING  FIRE  HOLES  AND  DISCHARGE. 

FIG.  128.  FIG.  129. 


-SECTION  THROUGH  CENTER. 


ELEVATION. 


a — Area  of  kiln,  5  feet  diameter,  15  feet  to  bottom  or  cone,  b — Fire  holes,  18  inches  by  3  feet,  c — 
Opening  and  door  for  discharge,  d—  Opening  and  door  for  feeding,  e— Fire  brick  lining,  9  inches. 
/—Iron  shell,  g—  Sight  hole. 

In  order  to  secure  a  regular  draft  in  burning  the  calcine,  the 
clay  should  all  be  thrown  into  the  kiln  in  lump  form,  fresh  from 
25 


386  BRICK,  TILES    AND   TERRA-COTTA. 

the  mine,  so  that  it  is  not  air  shaken  and  liable  to  break  up 
when  discharged  from  car  to  kiln,  as  the  small  clay  would  have 
a  tendency  to  check  the  draft. 

A  calcine  kiln  of  the  size  shown  in  illustrations  would  produce 
ten  tons  of  good  calcine  each  day.  A  smaller  kiln  with  three 
fire-holes  would  work  equally  as  well,  of  course  yielding  a  less 
quantity  of  calcine. 

SILICA    FIRE-BRICK. 

This  class  of  refractory  brick,  also  called  "Dinas"  fire-brick 
and  British  silica  fire-brick,  consists  almost  entirely  of  silica, 
and  was  invented  by  the  late  Mr.  W.  Weston  Young,  a  land- 
surveyor,  of  Newton-Nottage,  Glamorganshire,  Wales. 

The  company  first  established  to  manufacture  this  kind  of 
brick  was  organized  by  the  inventor  in  the  year  1822.  The 
material  at  the  "Dinas"  (the  well-known  rock  of  that  name  in 
the  Vale  of  Neath),  from  which  Mr.  Young  procured  it,  is 
nearly  pure  silex;  but  from  its  lying  on  the  limestone  and 
occasionally  intermixing  with  it,  there  is,  taking  the  average  of 
the  general  working,  perhaps  about  five  per  cent,  of  calcareous 
matter  and  one  per  cent,  of  metallic,  either  iron  or  copper. 
The  Dinas  rock  is  believed  to  be  the  millstone  grit  of  the  Car- 
boniferous System,  and  the  geological  equivalent  of  the  bed, 
termed  "ganister"  at  Sheffield,  England,  which  is  used  as  a 
lining  for  the  Bessemer-converter,  as  well  as  for  the  manufac- 
ture of  fire-brick  now  conducted  in  that  locality. 

The  use  of  the  " Dinas"  was  discovered  about  1790,  when  the 
fine  part  of  it  was  taken  to  one  of  the  copper  works  and  used  as 
a  cement,  and  for  mending  their  furnaces  while  at  work,  by 
placing  it  with  a  long  iron-handled  ladle  or  spade  where  the 
wash  of  the  metal  had  destroyed  the  brick ;  and,  from  its  re- 
markable property  of  swelling  in  high  heats,  it  fixed  itself 
firmly.  It  gradually  gained  from  one  copper  work  to  another 
till  its  use  became  general ;  in  fact,  they  are  not  able  to  find 
any  other  sand  that  will  answer  the  purpose  so  well.  Its  fire- 
proof qualities  being  known,  m,any  attempts  were  made  to  pro- 


THE   MANUFACTURE    OF   FIRE-BRICK.  387 

duce  a  brick  from  it;  but  all  the  common  combinations  of 
different  clays,  etc.,  failed. 

When  set  in  its  own  cement,  for  very  high  and  long  con- 
tinued heats  "  Dinas "  or  silica  brick  will  exceed  in  duration 
any  other  known  brick.  It  does  not  suit  every  situation,  as,  in 
fact,  no  fire-brick  will.  The  nature  of  it  at  once  tells  you  it 
must  not  be  placed  near  alkaline  substances;  neither  will  the 
effluvia  from  some  lead-ores  suit  it.  Perhaps  it  does  not  exceed 
Stourbridge  brick  for  gates ;  but  for  the  bodies  of  furnaces  of 
most  kinds  it  exceeds,  as  said  before,  that  and  every  other 
known  brick  in  duration.  The  manner  in  which  the  brick  is 
made  gives  it  a  rough  coat  compared  with  most  others  ;  indeed 
it  is  peculiar  in  this  respect.  But,  as  it  is  made  in  machines 
perfectly  square,  all  the  managers  of  iron  and  steel  works 
prefer  it  with  a  rough  coat ;  they  say  it  sets  better  in  the  work. 
This  brick  ought  to  be  kept  dry  if  possible,  for  being  open  in 
its  texture,  it  imbibes  moisture  freely.  The  fire-place,  roofs, 
sides,  and  bridge  of  the  furnace,  also  the  lower  part  of  the 
stack,  should  be  built  of  " Dinas;"  the  back  part  and  the  re- 
mainder of  the  stack  will  do  best  if  built  of  No.  I  fire-brick, 
and  the  slabs  for  leaving  the  flues  and  doors  are  also  best  made 
of  this  material. 

One  of  the  troubles  of  clay  brick,  which  silica  brick  escapes, 
is  its  so-called  "  dropping "  when  placed  in  the  roof.  This 
means  either  one  of  two  things — first,  that  a  crack  has  formed 
across  the  brick  which  leaves  a  piece  free  enough  to  fall  when 
any  change  of  temperature  loosens  it — this  is  the  peculiar 
property  of  a  pure  clay;  and  second,  the  formation  of  a  crust 
of  fused  clay  and  ashes  on  the  surface  which  cracks  off  and 
falls  when  the  brick  cools. 

In  the  construction  of  open-hearth  steel  and  glass  furnaces 
in  the  United  States,  silica  brick  have  taken  the  place  of  the 
highest  grades  of  fire-brick,  and  now  that  high  grade  silica 
brick  of  domestic  manufacture  are  to  be  had,  their  use  is 
rapidly  extending  to  other  furnaces. 

All  silica  brick  expand  under  the  action  of  high  heats.     The 


388  BRICK,  TILES   AND   TERRA-COTTA. 

expansion  of  the  best  silica  brick  of  American  manufacture 
varies  from  one-eighth  to  three-sixteenths  of  an  inch  per  foot 
according  to  the  temperature  carried  in  the  furnaces  in  which 
they  are  used. 

This  expansion  should  be  provided  for  in  some  manner  in 
building  furnaces,  and  this  is  done  in  various  ways.  Some 
users  of  silica  brick  merely  loosen  the  tie-bolts  of  the  furnace 
as  it  heats  up.  Others  insert  a  thin  board  (say  one-half  inch) 
every  four  feet  across  the  roof  of  the  furnace,  to  allow  for  the 
longitudinal  expansion,  and  the  board  burns  out  on  the  furnace 
heating  up,  the  space  being  filled  up  by  the  expanding  brick. 

With  circular  furnaces,  some  arrange  for  the  expansion  of 
the  roof,  with  a  series  of  plates  and  sets-crews,  which  are 
loosened  as  the  furnace  heats  up. 

Arches  over  doors  and  openings  may  have  an  occasional 
shingle  built  into  the  joints  to  provide  for  expansion. 

With  straight  walls  a  slip  joint  can  be  arranged  that  will 
<:lose  up  when  the  furnace  heats.  Care  should  be  taken,  how- 
ever, not  to  allow  for  more  expansion  than  will  actually  take 
place,  as  otherwise  there  will  be  an  open  joint  that  may  prove 
a  weak  point. 

All  users  of  silica  brick  should  strictly  observe  the  following 
rules : 

ist.  That  the  brick  are  kept  perfectly  dry. 

2d.  That  in  building,  the  brick  are  not  laid  too  tight. 

3d.  That  ample  provision  is  made  for  the  expansion  of  the 
brick  as  the  heat  is  raised,  without  weakening  the  support  of 
the  furnace. 

4th.  That  great  care  be  taken  in  heating  up  the  furnace  to 
do  it  slowly. 

5th.  That  the  same  material  be  used  in  laying  the  silica  brick 
as  that  from  which  the  brick  are  made. 

6th.  That  when,  for  any  reason,  it  becomes  necessary  to  cool 
down  the  furnace,  it  be  done  as  gradually  and  slowly  as  pos- 
sible. 

The  appearance  of  the  "  Dinas  "  brick  is  peculiar  in  its  color 


THE    MANUFACTURE    OF    FIRE-BRICK.  389 

and  in  the  roughness  of  its  surface.  Silica  brick  should  be 
regular  in  size,  thoroughly  burned,  and  the  chemical  analysis 
of  brick  made  by  the  same  manufacturer  at  different  times 
should  show  perfect  uniformity  in  quality,  and  these  require- 
ments only  can  be  secured  by  the  most  intelligent  and  unceas- 
ing watchfulness  in  all  the  details  which  pertain  to  the  produc- 
tion of  this  high  grade  of  refractory  material. 

The  way  of  manufacturing  "  Dinas  "  or  silica  brick  for  many 
years  was  a  closely  guarded  secret,  and  it  is  only  of  recent  date 
that  there  has  been  any  certain  knowledge  of  the  mode  of  pro- 
ducing such  brick. 

The  material,  or,  as  it  is  locally  named  in  Wales,  "  clay,"  of 
which  silica  brick  is  made,  is  found  at  several  places  in  the  Vale 
of  Neath.  It  occurs  in  the  state  of  rock  and  disintegrated  like 
sand.  Its  color,  when  dry,  is  pale-gray.  The  rock,  when  not 
too  hard,  is  crushed  to  coarse  powder  between  iron  rolls.  By 
exposure  to  the  air  the  hard  rock  becomes  somewhat  softer,  but 
some  of  it  is  so  hard  that  it  cannot  be  profitably  employed  with- 
out the  use  of  a  Blake  or  other  crusher.  The  composition  of 
Dinas  "  clay,"  from  two  localities  in  the  Vale  of  Neath,  has 
been  found  to  be  as  follows : 

COMPOSITION    OF    DINAS    "  CLAY." 

I.  II. 

Silica 98.31  ,  96.73 

Alumina 0.72  1.39 

Protoxide  of  iron o.  1 8  0.48 

Lime 0.22  0.19 

Potash  and  soda o.  14  0.20 

Water  combined 0.35  0.50 


99.92  99.49 

These  analyses  were  made  by  Prof.  W.  Weston.  No.  I  was 
rock  of  medium  hardness,  which  was  obtained  near  Point  Neath 
Vaughan,  and  No.  II  was  from  the  same  locality,  though  not 
from  the  same  mine.  The  powder  of  the  rock  is  mixed  and 
ground  in  a  9  foot  wet-pan  with  about  I  y2  per  cent,  of  lime, 


390  BRICK,  TILES   AND   TERRA-COTTA. 

and  sufficient  water  to  make  it  cohere  slightly  by  pressure. 
A  sober  man  should  be  employed  to  see  that  the  ingredients 
used  in  giving  the  brick  the  bond  are  very  evenly  distributed 
in  the  pan,  as  this  is  one  of  the  most  important  things  to 
do  in  order  to  have  the  brick  uniform  in  size.  Good  men 
should  be  employed  at  the  pan,  men  who  will  see  that  every 
pan  of  the  material  is  ground  alike,  as  in  no  case  should  one 
pan  be  ground  fine  and  the  next  pan  ground  coarse.  Every 
pan  of  material  should  be  ground  alike,  or  the  brick  cannot  be 
made  uniform  in  size,  as  the  expansion  will  be  greater  in  some 
brick  than  others.  The  mixture  of  ground  quartz  and  lime  is 
pressed  into  iron  moulds,  of  which  two  are  fixed  under  one 
press,  side  by  side.  The  mould,  which  is  smaller  than  the 
brick  is  to  be,  is  open  at  the  top  and  bottom,  like  ordinary 
brick  moulds,  is  closed  below  by  a  movable  iron  plate,  and 
above  by  another  plate  of  iron,  which  fits  in  like  a  piston,  and 
is  connected  with  a  lever.  The  machine  being  adjusted,  the 
coarse  mixture  is  put  into  the  moulds  by  a  workman,  whose 
hands  are  protected  by  stout  gloves,  as  the  sharp  edges  of  the 
fragments  would  otherwise  wound  them.  The  moulds  having 
been  perfectly  filled,  the  piston  is  then  pressed  down,  after 
which  the  bottom  plate  of  iron  on  which  the  brick  is  formed  is 
lowered  and  taken  away  with  the  brick  upon  it,  as  it  is  not 
sufficiently  solid  to  admit  of  being  carried  in  the  usual  man- 
ner. The  brick  are  dried  on  these  plates  upon  hot  floors 
warmed  by  flues  passing  underneath ;  and  then  they  are 
pressed  in  hand  presses  and  put  on  a  floor  made  twice  as  hot 
as  the  floor  they  are  moulded  on,  so  they  will  dry  very  quickly. 
The  Savage  Fire  Brick  Co.,  Hyndman,  Pa.,  uses  with  most 
satisfactory  results  several  Raymond  Power  Represses  made  by 
C.  W.  Raymond  &  Co.,  Dayton,  Ohio,  for  pressing  silica  fire- 
brick. When  dry  they  are  piled  on  end,  usually  in  circular 
down-draft  kilns,  similar  to  kilns  in  which  ordinary  fire-brick 
are  burned.  The  brick  must  be  set  in  one  kiln  properly. 
Every  head  or  bench  should  be  perfectly  level,  so  that  the  brick 
can  settle  evenly,  and  the  setter  should  be  very  careful  to  allow 


THE   MANUFACTURE    OF   FIRE-BRICK.  391 

enough  room  for  expansion.  About  8  days'  hard  firing  are  re- 
quired for  these  brick,  and  about  the  same  time  for  the  cooling 
of  the  kiln.  The  cooling  can  not  be  hastened  without  detri- 
ment to  the  brick.  One  kiln  containing  50,000  brick  consumes 
65  tons  of  coal,  half  free-burning,  and  half  binding.  The  heat 
required  to  burn  a  silica  brick  is  so  high  as  to  burn  a  second- 
grade  fire-brick  to  a  running  mass.  In  the  burning  of  silica 
brick  the  heat  has  to  be  equal  to  the  highest  grade  of  fire-brick 
and  has  to  be  held  fully  twenty-four  hours  longer  than  for  the 
highest  grade  of  fire-brick  made  from  the  non-plastic  or  flint 
fire-clays.  Silica  brick  are  manufactured  of  various  shapes  and 
sizes,  to  suit  the  furnace  builder. 

The  fractured  surface  of  these  brick  is  uneven,  showing 
coarse  irregular  white  particles  of  quartz,  surrounded  by  a 
small  quantity  of  light-brownish  yellow  matter.  The  lime 
which  is  added  exerts  a  fluxing  action  on  the  surface  of  the 
fragments  of  quartz,  and  so  causes  them  to  stick  together. 
From  their  silicious  nature  it  is  obvious  that  silica  brick  should 
not  be  exposed  to  the  action  of  slags  rich  in  metallic  oxides. 

So  scrupulous  are  the  managers  of  some  works  producing 
silica  brick  that  they  cause  the  silica  to  be  weighed  after  com- 
ing from  the  Blake  crusher  and  before  being  put  in  the  wet- 
pan  ;  the  same  care  being  exercised  in  determining  the  quantity 
of  lime  admitted  into  the  wet-pan  with  the  charge  of  silica  to 
be  ground.  Other  manufacturers  of  silica  brick  do  not  weigh 
the  constituent  materials,  but  judge  the  proper  mixture  by  the 
consistency  of  the  lime  liquid  and  by  the  stiffness  of  the  ground 
mass.  The  silica  material  is  ground  and  mixed  in  all  respects 
the  same  as  for  ordinary  fire-brick.  The  greatest  watchfulness 
is  required  to  be  observed  in  the  preparation  of  the  lime  liquid 
which  forms  the  bond  or  binding  material  which  unites  the 
silica.  The  quantity  of  lime  contained  in  the  mixture  must  not 
be  excessive — it  should  not  exceed  two  per  cent,  of  the  entire 
body  in  the  best  grade  of  silica  brick.  The  knowledge  of  the 
manner  in  which  the  binding  material  is  prepared  so  as  to  ob- 
tain the  best  possible  results  from  the  smallest  quantity  of  lime 


392  BRICK,  TILES    AND   TERRA-COTTA. 

is  one  of  the  principal  points  where  the  practical  experience  of 
men  trained  in  the  business  of  silica  brick  manufacture  is  of 
great  value. 

The  lime  used  as  a  binding  material  in  the  manufacture  of 
silica  brick  is  dissolved  in  a  board  box  similar  to  that  used  by 
plasterers,  and  from  this  box  the  lime  is  run  in  a  thin  state  into 
the  settling  vat.  From  this  settling  vat  the  lime  is  gently  de- 
canted into  the  third  vat  or  barrel,  care  being  observed  that 
none  of  the  thick  sediment  from  the  lime  is  taken  up  from  the 
bottom  of  the  settling  vat.  It  is  necessary  that  the  lime  should 
be  as  nearly  pure  as  it  is  possible  to  get  it,  as  also  the  carbon- 
ate of  lime  which  is  in  part  used.  In  the  third  vat  or  barrel 
there  is  placed  a  spiral  agitator  which  lifts  the  material  always 
from  the  bottom  of  the  vat  or  barrel,  thereby  keeping  the  lime 
of  a  uniform  consistency  and  preventing  the  heavier  particles 
of  lime  from  settling  to  the  bottom  of  the  vat  or  barrel  from 
which  the  lime  solution  'is  run  by  means  of  a  small  pipe  into 
the  wet-pan,  to  be  there  incorporated  with  the  silica  which  is 
being  prepared  for  the  moulders. 

There  are  several  firms  in  the  United  States  at  present 
engaged  in  the  manufacture  of  silica  brick,  among  which  are 
Harbison  &  Walker  Co.,  Pittsburgh,  Pa. ;  The  Savage  Fire- 
Brick  Co.,  Hyndman,  Pa. ;  Reese,  Hammond  &  Co.,  Bolivar, 
Pa. ;  A.  J.  Haws  &  Son,  Johnstown,  Pa.  A  large  part  of  the 
quartz  used  by  the  manufacturers  of  silica  brick  in  the  State  of 
Pennsylvania  is  quarried  in  Wills  Mountain,  Pa. 

Great  care  should  be  used  in'selecting  the  silica  quartz;  and 
in  order  to  do  so,  good  reliable  men  should  be  employed  in 
the  quarry,  men  who  are  acquainted  with  the  quartz,  as  this  is 
most  important. 

The  silica  brick  now  made  in  the  United  States  by  the  lead 
ing  manufacturers  will   equal    in    quality  the  imported   Dinas 
material. 

The  following  is  the  result  of  an  analysis  of  one  of  the 
"Star  Silica"  brick: 


THE   MANUFACTURE    OF   FIRE-BRICK.  393 

CARNEGIE,  PHIPPS  &  Co.,  LIMITED, 

PITTSBURGH,  Feb.  16,  1891. 
MESSRS.  HARBISON  &  WALKER,  Pittsburgh. 

Gentlemen: — The  report  below  gives  the  analysis  made  at  our  Homestead  Works, 
of  Silica  Brick  of  your  manufacture  : 

"  STAR." 

Silica 96.02 

Alumina J  • !  3 

Peroxide  of  Iron 0.72 

Lime 2.10 

Magnesia 0.02 

Yours  very  truly, 

OTIS  H.  CHILDS,  Sec'y. 

Consumers  of  silica  brick  not  infrequently  complain  that  the 
analyses  given  by  manufacturers  of  silica  brick  are  very  differ- 
ent from  the  results  obtained  by  them,  when  they  analyze  the 
brick  received,  and  hence  if  a  manufacturer  intends  to  maintain 
the  standard  desired  for  his  brands  ii  silica  brick  he  must  be 
ever  watchful  and  cautious  in  all  that  pertains  to  the  details  of 
their  production. 

One  of  the  principal  items  of  cost  in  the  manufacture  of 
silica  brick  is  the  expense  for  fuel,  and  when  the  burning  is 
done  with  solid  fuel,  such  as  coal,  the  labor  of  handling  the 
large  quantities  of  coal  and  resulting  ashes  is  also  very  costly. 

In  order  to  lessen  the  fuel  and  labor-costs  of  burning  silica 
brick  The  Gleboing  Union  Fire-Clay  Co.,  Limited,  of  Glasgow, 
Scotland,  and  Messrs.  J.  Grayson,  Lowood  &  Co.,  of  Sheffield, 
England,  as  well  as  a  large  number  of  other  silica  brick  manu- 
facturers in  Europe  and  the  Harbison  &  Walker  Co.,  of 
Pittsburgh,  Pa.  have  adopted  the  Dunnachie  continuous 
regenerative  gas  kiln,  which  gives  a  better  and  more  uniform 
brick  than  can  be  obtained  by  direct  firing.  The  brick  made 
by  Messrs.  J.  Grayson,  Lowood  &  Co.,  are  made  from  the 
material  locally  termed  "ganister"  and  are  principally  em- 
ployed for  lining  the  Siemens-Martin  furnaces  and  other  fire- 
places exposed  to  a  high  degree  of  heat.  According  to  G.  J. 
Snelus,  the  composition  of  these  brick  is  as  follows :  Silica, 
95.4  per  cent.,  alumina,  3.10  per  cent.,  and  lime,  1.68  per  cent. 


*fy>x 

OF  THE  \ 

UNIVERSITY) 
^AL^QHW*^ 


394  BRICK,  TILES   AND   TERRA-COTTA. 

The  brick,  it  is  claimed,  have  the  advantage  of  not  expanding 
at  a  high  temperature. 

CARBON    FIRE-BRICK    FOR    FURNACES. 

For  the  preparation  of  these  brick,  coke  is  ground  and  sifted 
and  intimately  mixed  with  about  twenty  per  cent,  of  tar,  the 
mixing  being  under  certain  conditions  effected  in  a  somewhat 
warm  state.  The  extraordinarily  plastic  mass  is  then  stamped 
in  thin  layers  into  sheet-iron  boxes,  which  can  be  closed  with 
hinge-joints,  care  being  had  in  filling  in  new  mass  to  always 
scratch  up  the  surface.  The  brick  cannot  be  taken  from  the 
mould,  but  remain  in  it  for  drying,  which  requires  about  four- 
teen days.  The  manufacture  scarcely  differs  from  that  of  ordi- 
nary fire-brick.  In  burning  the  brick  the  air  has,  however,  to 
be  entirely  excluded ;  even  the  interspaces  in  the  muffles  are 
filled  up  with  coke  dust.  By  heating,  the  brick  become  first 
soft  and  try  to  expand,  "which,  however,  is  prevented  by  the 
coke  dust. 

The  manufacturers  usually  use  for  the  purpose  muffles  of 
crude  clay  which  burn  to  chamotte.  It  is  unnecessary  to  re- 
mark that  everything  must  be  thoroughly  luted  to  prevent  the 
access  of  air.  By  burning  the  tar  carbonizes  and  forms  a  solid 
mass  with  the  particles  of  coke.  Hence  the  manufacture  of 
these  brick,  whether  large  or  small,  presents  no  especial  diffi- 
culties. 

As  long  as  the  Enskirchen  steam  brickyard  at  Mechernich 
had  the  monopoly  of  the  manufacture  of  these  brick  in  Ger- 
many, the  forms  prescribed  there  had,  of  course,  to  be  accepted. 
However,  this  is  now  changed,  and  well-shaped  brick  20  to  32 
inches  long,  20  inches  thick,  and  7^  inches  wide  are  now 
manufactured. 

The  price  of  these  brick  is  at  present  twice  that  of  ordinary 
refractory  brick  for  furnaces.  They  are,  however,  specifically 
much  lighter,  the  weight  per  one  cubic  yard  being  about  2640 
pounds,  whilst  at  least  4400  pounds  must  be  calculated  for  fire- 
brick. 


THE    MANUFACTURE    OF   FIRE-BRICK.  395 

Carbon  brick  were  at  first  only  used  for  hearth  blocks  and 
the  hearth  up  to  the  tuyeres,  but  at  present  the  boshes  are  also 
built  of  these  brick,  which  must  be  considered  an  advance  of 
great  importance  since  the  danger  of  the  charge  remaining  sus- 
pended can  thereby  be  avoided. 

Great  practical  difficulties  were  encountered  in  placing  the 
brick  in  position.  After  being  rubbed  smoothly  upon  each 
other,  they  had  to  be  warmed  and  the  tar,  which  served  as 
mortar,  applied  warm.  The  workmen  suffered  much  from  the 
tar  vapors,  ulcers  and  boils  being  formed  on  the  hands  and 
eyes.  This  mode  of  setting  the  brick  is  now,  however,  done 
away  with,  a  mortar  four  parts  coke  powder  and  one  part  fine 
red  clay  being  at  present  used. 

GLASS  POTS. 

The  practical  success  of  the  "  tank  "system  "  of  glass  manu- 
facture has  not  as  yet  curtailed  the  demand  for  glass  melting 
pots.  These  pots  are  composed  of  clay,  which  is  required  to 
be  as  free  as  possible  from  lime  and  iron.  A  clay  obtained 
from  the  carboniferous  shales  of  Worcestershire,  in  the  neigh- 
borhood of  Stourbridge,  England,  is  highly  esteemed  for  the 
manufacture  of  glass  pots.  There  are  also  several  American 
and  German  clays  which  are  suitable  for  the  purpose  of  pro- 
ducing the  large  pots  in  which  glass  is  melted  and  worked. 

These  clays  are,  ist,  Gross  Almerode,  near  Coblentz,  Ger- 
many, for  bond  clay;  2d,  Christy  clay,  from  near  St  Louis, 
Mo.,  used  for  calcine  and  bond ;  3d,  Blue  Ridge,  Missouri, 
clay,  used  for  bond  and  calcine ;  4th,  Mineral  Point,  Ohio, 
flint  clay,  used  as  flint  and  calcine  ;  5th,  old  pot  shells  for  cal- 
cine. 

The  German  clay  is  shipped  as  ballast  in  the  holds  of  ves- 
sels, and  hence  transportation  costs  but  little.  It  is  an  ex- 
cessively fine-grained  and  heavy  clay,  and  is  very  plastic,  mak- 
ing a  better  bond  than  any  native  clay.  It  comes  in  blocks 
9x6x6  inches,  which  have  to  be  pared  with  a  draw-knife,  and 
then  broken  and  inspected  and  all  irony  spots  removed.  No 


396  BRICK,  TILES   AND   TERRA-COTTA. 

pieces  larger  than  a  walnut  are  allowed  to  go  into  the  mixture. 
The  work  involved  in  getting  the  clay  ready  for  use  is  exces- 
sive, and  it  is  the  opinion  of  those  at  the  works  that  it  is  much 
overrated.  It  is  an  excellent  bond  clay,  it  is  true,  but  its  re- 
fractory properties  are  excelled  by  the  Christy  clay  of  Missouri. 

These  Missouri  clays  come  in  blocks,  either  calcined  or  raw. 
They  are  pared  and  broken,  but  not  sorted  over.  They  are 
washed  before  shipping,  so  that  they  are  much  finer  than  in 
nature.  The  Blue  Ridge  is  the  finer-grained  of  the  two.  The 
Mineral  Point  calcined  clay  is  not  now  largely  used,  because 
the  old  pot-shells,  being  already  in  the  desired  composition  of 
the  mixture,  make  a  better  calcine  than  any  single  clay. 

These  shells  are  chipped  with  small  hammers  until  no  part  of 
the  surface  remains  and  only  the  clean  interior  is  left.  The 
charge  is  composed  quite  largely  of  calcine  with  a  little  flint 
clay,  and  the  remainder  German  and  Missouri  bond  clays.  The 
mixture  is  ground  in  a  dry  pan  and  sifted  in  a  jig  bolt,  and  the 
coarse  part  re-ground.  It  is  then  pugged  five  or  six  times  in 
succession,  and  then  is  stored  and  blanketed.  It  remains  in  this 
state  until  it  sours  and  smells  offensively,  which  the  men  claim 
is  necessary  to  its  proper  working.  It  is  wedged  by  hand  and 
is  ready  for  use. 

When  required  for  forming  the  pots,  a  sufficient  quantity  of 
of  the  clay  is  taken  and  kneaded  with  one-fourth  of  its  quantity 
of  the  material  of  old  pots,  which  are  ground  to  fine  powder  and 
carefully  sifted ;  this  material  gives  firmness  and  consistency  to 
the  paste,  and  renders  it  less  liable  to  be  affected  by  the  heat. 
The  pots  are  of  two  kinds,  the  open  and  the  covered.  The 
first  are  used  for  melting  common  glass,  such  as  window 
and  bottle  glass ;  the  other  for  flint  glass.  In  each  case,  the 
pots  are  made  entirely  by  hand,  and  require  great  skill  and  care. 

The  pots  are  large  structures  about  five  feet  high,  four  feet 
wide,  and  four  feet  long,  bounded  on  top  and  side  by  covered 
walls,  and  on  the  bottom  by  a  flat  face.  They  weigh  from 
2,000  to  3,000  pounds,  and  sometimes  as  much  as  3,500 
pounds.  They  are  made  from  three  to  five  inches  thick  with  a 


THE    MANUFACTURE    OF   FIRE-BRICK.  397 

thicker  floor,  and  are  each  built  on  a  small  platform  covered 
with  gravel,  so  that  the  air  may  circulate  beneath  them  and  dry 
them  faster. 

The  flint  glass  pots  are  only  from  two  to  three  inches  thick- 
Each  builder  has  on  hand  twelve  or  fifteen  pots  at  once,  on 
which  he  daily  builds  a  little  more,  until  at  the  end  of  three 
weeks  or  a  month  he  finishes  them  all  together.  The  buildings 
in  which  glass  pots  are  made  are  provided  with  elevators  so  that 
the  heavy  pots  can  be  handled  without  danger  of  injuring  them. 

When  the  bottom  is  finished,  the  workman  begins  to  build 
up  the  side  of  the  pot  by  first  forming  a  ring  of  the  same 
height  all  round,  taking  care  to  round  off  the  upper  edge  to  a 
semicircular  curve  of  great  regularity;  upon  this  he  begins 
bending  over  other  lumps  of  the  paste  until  another  equal 
layer  is  formed,  and  these  are  continued  until  the  pot  is  com- 
plete ;  the  workmen  spread  wet  clothes  over  the  edges  when 
they  discontinue  working.  This  is  necessary,  to  admit  of  a 
certain  amount  of  drying,  otherwise  the  large  weight  of  clay 
used  would  prevent  the  form  being  kept,  and  the  pot  would 
either  fall  to  pieces  or  lose  shape ;  the  building  of  the  pot  is 
consequently  extended  over  several  days.  After  the  potter 
has  finished  his  work,  the  pots  are  removed  into  the  first  dry- 
ing floor,  where  they  are  only  protected  from  draugnts,  so  that 
the  drying  may  be  conducted  with  the  greatest  possible  uni- 
formity. When  they  have  progressed  sufficiently,  they  are 
removed  to  the  second  drying  floor,  which  is  heated  with  a 
stove,  and  the  drying  is  here  completed.  They  are  then  placed 
in  the  store,  where  usually  a  good  stock  is  kept  on  hand,  as 
time  improves  them,  and  they  are  seldom  kept  less  than  six  or 
nine  months. 

The  pots  are  shipped  on  three-wheeled  trucks,  which  are  re- 
turned to  the  works,  so  that  they  are  loaded  and  unloaded  with 
ease  and  security,  where  before  there  was  always  great  danger 
of  breaking  down.  The  work  must  be  under  most  intelligent 
supervision. 

When  required  for  use,  the  pots  are  placed  for  four  or  five 


398  BRICK,  TILES   AND   TERRA-COTTA. 

days  in  the  annealing  furnace,  which  is  on  the  reverberator^ 
principle,  and  they  are  there  kept  at  a  red  heat.  This  furnace 
is  so  situated,  that  the  pots,  when  ready,  can  be  very  quickly 
transferred  to  the  main  furnace — an  operation  of  exceeding  dif- 
ficulty, and  requiring  great  skill  and  dexterity,  as  they  have  to 
be  removed  whilst  red  hot,  and  it  must  be  done  so  quickly  that 
no  sudden  cooling  shall  injure  the  pot,  a  difficulty  which  can 
only  be  understood  by  remembering  that  the  ordinary  pots  are 
nearly  four  feet  in  depth,  are  the  same  in  width  at  the  mouth 
by  about  thirty  inches  at  the  bottom,  and  they  weigh  several 
hundred-weight.  The  enormous  amount  of  labor  bestowed 
upon  these  pots  makes  them  very  expensive.  Their  removal 
from  the  annealing-oven  to  the  main  furnace  is  effected  by  an 
immense  pair  of  forceps  several  feet  in  length,  which  are 
placed  horizontally  upon  an  upright  iron  pillar  about  three 
feet  in  height,  which  rises  from  a  small  iron  truck  on  four  wheels, 
so  that  the  whole  apparatus  can  be  easily  moved  from  place  to 
place.  By  means  of  this  instrument  the  pot  is  lifted  and  dex- 
terously withdrawn  from  the  oven,  and  as  quickly  transferred 
to  its  position  in  the  main  furnace,  in  which  usually  10  or  12 
are  placed  on  a  platform  of  fire-brick  or  stone,  each  pot  being 
opposite  to  a  small  arched  opening  through  which  it  can  be 
filled  and  emptied.  The  entrance  to  the  main  furnace,  through 
which  the  pots  have  been  introduced,  is  then  closed,  with  a 
movable  door  of  fire-brick,  and  covered  over  with  fire-clay,  to 
prevent  the  escape  of  the  heat. 

The  material  used  in  the  construction  of  the  arches,  as  well 
as  walls  of  large  glass  ovens,  is  best  produced  from  the  Stour- 
bridge  or  similar  clay,  which  is  carefully  shaped  into  large 
slabs,  and  faithfully  dried  for  more  than  a  year ;  but  it  is  not 
burned  in  the  kiln. 

Some  of  the  leading  manufacturies  of  fire-brick  keep  on  hand 
various  sizes  of  jack  brick,  and  are  also  prepared  to  make  any 
special  shape  of  jack  or  glass  pot  stopper  that  may  be  wanted, 
and  keep  them  on  hand  for  any  customer  using  them  regularly. 
For  the  crowns  of  furnaces,  brick  are  made  to  any  pattern  that 


THE   MANUFACTURE    OF    FIRE-BRICK.  399 

may  be  desired — but  usually  twelve  inches  long,  with  the 
lines  tapering  to  suit  the  radial  lines  of  the  furnace.  For  those 
glass  manufactures  who  have  mills  and  are  prepared  to  manu- 
facture their  own  shapes,  the  fire-brick  manufacturers  keep  a 
large  stock  of  different  clays  on  hand,  calcined  and  green.  The 
calcined  clay  should  be  all  carefully  selected  and  thoroughly 
burned. 

For  building  the  eyes  of  furnaces,  repairing  benches  and  mak- 
ing flue-brick,  etc.,  fire-brick  manufacturers  carry  a  stock  of 
batch  clay  which  should  be  prepared  very  stiff  so  as  to  require 
thorough  ramming  in  order  to  get  it  securely  in  its  place ;  and 
the  same  stock  when  desired  can  be  made  into  blocks  to  form 
the  eye,  and  burned. 

GAS    RETORTS. 

Fire-clay  gas  retorts  have  almost  entirely  replaced  the  old 
form  of  iron  retorts,  as  they  possess  when  properly  made  the  ex- 
cellent advantage  of  neither  expanding  nor  contracting  upon 
being  heated  and  cooled. 

In  Figs.  130  to  135  are  illustrated  the  various  forms  of  gas  re- 
torts in  common  use. 

The  manufacture  of  clay  retorts  for  making  gas  is  now  car- 
ried on  largely. 

The  clay  body  is  compounded  to  stand  considerable  heat 
without  any  tendency  to  soften,  for  so  large  a  piece  of  hollow 
ware  must  be  refractory  to  maintain  even  its  own  weight  at  the 
temperature  used.  The  mixture  requires  more  care  in  com- 
pounding than  a  brick  mixture,  for  more  is  involved  in  the 
failure  of  a  retort  to  do  good  service  than  a  few  brick.  Calcine 
is  used  in  large  amount,  but  crushed  rather  finer  than  common, 
and  it  needs  a  very  good  and  plastic  bond  clay. 

The  retort  is  shaped  from  the  tempered  clay  by  filling  the 
space  between  a  large  sheet-iron  shell  and  a  wooden  core.  The 
shell  is  placed  in  position  and  the  floor  covered  with  clay  four 
inches  deep  and  tamped.  The  core  is  then  introduced  and 
adjusted  so  that  four  inches  separate  it  from  the  walls  on  all 


400 


BRICK,  TILES   AND   TERRA-COTTA. 


sides.  The  clay  is  filled  in  small  amounts  at  a  time  and 
tamped  gently.  When  the  retort  is  high  enough,  the  core  is 
withdrawn  by  a  crane  and  the  mouth  of  the  retort  built  by 


1 


0 


hand.  The  shell  is  then  unbolted  and  removed  in  two  pieces, 
and  the  finished  retort  is  standing  on  its  end.  It  is  left  to  dry 
for  several  weeks  in  this  position,  and  is  finally  removed  to  the 


THE   MANUFACTURE    OF   FIRE-BRICK. 


401 


kiln  to  be  burnt.  It  is  put  into  an  ordinary  fire-brick  kiln  and 
brick  are  piled  around  it  to  keep  it  in  position  without  sagging, 
and  when  in  steady  use,  and  never  allowed  to  cool,  they  prove 
very  durable. 

WEIGHTS   AND    SIZES    OF    GAS    RETORTS. 

Retorts  are  built  to  sizes  and  shapes  as  ordered,  and  to  fit  any  mouthpiece. 
The  more  usual  sizes  are  : 


D  SHAPE. 

Probable 
Weight  of 
Retort  9  feet 
long. 

ROUND  SHAPE. 

Probable 
Weight  of 
Retort  9  feet 
long. 

OVAL  SHAPE. 

Probable 
Weight  of 
Retort  9  feet 
long. 

18  in.  X  13  in.  inside, 

14  cwts. 
^      « 

13  in.  inside, 
14  " 

12    CWtS. 

13      ' 

18  in.  X  14  in.  inside, 

14  cwts. 

15      ' 

24  "    X  14  "      " 

17      ' 

16  " 

IS      ' 

22  "    X  14  "      " 

(24  "   X  14  " 

16      ' 
17      ' 

26 


CHAPTER  XL 

THE   MANUFACTURE   OF   ENAMELED   BRICK.* 
GENERAL    REMARKS. 

THE  art  of  enameling  brick  is  older  than  recorded  history. 
It  was  practiced  in  Assyria,  Babylonia  and  Chaldea.  The 
Moors  brought  the  art  with  them  from  the  East  when  they  ex- 
tended their  domain  into  Spain  and  over  Western  Europe. 
The  Moors  derived  their  knowledge  from  India,  and  primarily 
from  China.  With  the  decline  of  the  Moorish  civilization  the 
art  of  manufacturing  enamel  brick  and  tiles  was  lost  to  the 
Western  world,  still  being  retained,  however,  in  the  Orient. 

The  great  surviving  monument  of  Moorish  art  in  brick  and 
tile  enameling  is  the  interior  decorations  of  the  walls  of  the 
Alhambra  Palace  at  Granada,  in  Spain.  For  over  a  thousand 
years  knowledge  of  the  art  of  brick  and  tile  enameling  slum- 
bered in  Europe,  and  was  only  revived  when  the  Crusaders  from 
France  visited  Byzantium,  Palestine  and  Syria,  and  when 
returning  carried  to  France  knowledge  of  enamels  and  also 
workmen  skilled  in  their  application  to  clay  bodies.  From 
France  —  especially  from  Normandy  —  the  art  of  making 
enameled  brick  and  tiles  spread  through  continental  Europe 
and  to  England. 

With  the  vanishing  civilization  of  mediaeval  times  this  art  was 
again  lost  to  Europe.  It  has  only  been  during  the  past  forty 
years  that  the  manufacture  of  enameled  brick  has  again  been 
put  upon  a  successful  basis  in  England,  and  only  during  the 
past  twenty  years  that  it  can  be  said  to  have  become  financially 
profitable. 

*  A  lecture  delivered  by  Charles  T.  Davis  at  the  annual  meeting  of  the  National 
Association  of  Fire  Brick  Manufacturers  held  in  New  York  City,  December  2nd  and 
3rd,  1891. 

(402) 


THE    MANUFACTURE    OF   ENAMELED    BRICK.  403 

The  problem  which  now  confronts  us  is  "  Why  can  we  not 
manufacture  enameled  brick  which  will  compete  with  those  of 
England  in  both  quality  and  price?" 

There  is  only  one  answer  to  this  question — we  lack  specific 
knowledge  regarding  the  details  of  the  subject. 

Diodorus  Siculus  relates  that  the  brick  of  the  walls  of  Baby- 
lon, erected  under  the  orders  of  Semiramis,  were  decorated 
with  all  kinds  of  living  creatures  portrayed  in  various  colors 
upon  the  brick  before  they  were  burned, 

In  spite  of  this  positive  information  concerning  the  way  in 
which  the  enamel  decorations  were  applied  to  the  brick  which 
formed  the  facings  of  the  walls  of  Babylon,  nearly  all  persons 
who,  forty  years  ago,  endeavored  to  manufacture  enamel  brick, 
thought  that  it  was  necessary  to  enamel  the  brick  only  after 
they  had  been  once  burned.  The  loss  of  time,  the  injuries 
which  resulted  to  the  brick,  and  the  great  cost  incurred  in  first 
burning  the  brick,  then  enameling  them,  and  then  burning  the 
brick  the  second  time,  forced  the  manufacturers  of  this  class  of 
goods  to  abandon  such  wasteful  methods,  and  to  apply  the  en- 
amel to  the  brick  in  the  green  state  and  complete  the  burning 
process  in  one  operation.  A  brick  which  has  once  been  burned 
and  afterwards  enameled  and  again  burned  does  not  make  as 
good  a  product  as  is  had  by  the  one-burning  process,  as  the 
enamel  being  applied  to  the  dry  surfaces  does  not  adhere  firmly, 
and  commonly  scales  completely  off  after  the  brick  are  laid  in 
the  wall.  The  enameling  as  well  as  the  burning  of  the  brick 
must,  however,  all  be  done  in  one  firing,  and  if  done  otherwise 
the  results  will  be  neither  satisfactory  nor  profitable. 

It  will  readily  be  seen  from  the  foregoing  remarks  that  easily- 
fused  enamels,  such  as  those  containing  lead,  cannot  be  em- 
ployed, as  such  enamels  would  be  destroyed  in  the  heat  of  the 
kiln  and  pass  out  with  the  gases  long  before  the  brick  them- 
selves were  burned,  especially  as  the  brick  used  for  enameling 
are  made  from  fire-clay. 

Hence  it  is  of  primary  importance  for  enamel  to  coincide 
with  the  contraction  and  expansion  of  the  clay  body  to  which 


404  BRICK,  TILES   AND   TERRA-COTTA. 

it  is  applied.  It  is  also  necessary  that  enamels  should  not  be 
fusible  at  any  special  temperature,  as  the  fusing  point  of  en- 
amels must  vary  according  to  the  degree  of  heat  which  the  clay 
body  upon  which  they  are  placed  will  stand.  The  constituents, 
therefore,  which  form  the  enamel  must  be  of  such  a  character 
that  their  mixture  will  withstand  high  temperatures  without 
danger  or  injury,  and  the  brick  to  which  the  enamel  is  applied 
must  be  sufficiently  refractory  so  as  not  to  melt  or  get  out  of 
shape  during  the  time  when  the  enamel  is  being  attached  to  it 
in  the  firing  process. 

Manufacturers  of  enamel  brick  in  England  do  not  allow  their 
employes  to  become  conversant  with  all  the  details  which  relate 
to  the  production  of  this  class  of  wares.  A  man,  boy  or  girl 
once  employed  in  any  enamel  brick  works  in  the  old  country  is 
assigned  to  some  special  department  of  the  factory,  and  remains 
employed  in  that  same  department  so  long  as  he  or  she  may  be 
an  employe.  In  this  way  it  is  quite  impossible  for  the  employes 
in  an  enamel  brick  works  to  acquire  a  thorough  knowlege  of  the 
the  business  in  all  its  various  ramifications.  Should  an  employe 
of  one  enamel  brick  manufacturer  leave  his  place  and  seek  em- 
ployment with  some  other  manufacturer  of  enamel  brick  in  the 
same  neighborhood  with  a  view  of  extending  his  knowledge  of 
the  business,  he  is  foiled  by  the  surveillance  which  the  various 
manufacturers  maintain.  The  person  seeking  employment  is 
asked  upon  which  special  branch  of  work  he  was  last  employed, 
and  is  assigned  to  that  department,  if  employment  be  given  him. 
If  the  person  seeking  employment  states  that  he  was  employed 
in  some  branch  other  than  that  in  which  he  was  employed,  the 
fact  is  soon  discovered  by  lack  of  familiarity  and  skill,  and 
hence  such  persons  are  at  once  discharged,  and  it  becomes  a 
matter  of  impossibility  for  such  a  person  to  again  find  employ- 
ment in  that  particular  section  of  England.  In  this  way  the 
manufacturers  of  enamel  brick  are  protected,  and  their  em- 
ployes develop  a  high  degree  of  skill  and  become  experts  in  their 
various  departments  of  work.  But  this  special  knowledge 
never  becomes  general  knowledge,  and  hence  no  matter  how 


THE    MANUFACTURE   OF   ENAMELED    BRICK.  405 

expert  a  man  may  become  in  making,  pressing,  dipping,  set- 
ting, burning  or  sorting  enamel  brick,  there  is  no  possibility  for 
him,  under  the  English  system,  to  become  thoroughly  skilled 
in  all  the  departments  of  enamel  brick  manufacture.  Large 
sums  of  money  have  been  lost  in  the  United  States  by 
brick  manufacturers  who  do  not  understand  these  facts. 
They  naturally  thought  that  if  a  man  was  an  expert  burner,  or 
an  expert  in  any  other  department  of  enamel  brick  manufac- 
ture, that  he  was  an  expert  in  all  the  departments.  The  failures 
which  have  resulted  from  such  false  starts  have  done  much  in  the 
past  to  retard  in  this  country  the  successful  development  of  the 
art  of  enamel  brick  manufacture. 

One  great  point  in  which  manufacturers  of  enameled  brick  in 
the  United  States  will  be  for  a  long  time  deficient,  is  in  not  be- 
ing able  to  secure  skilled  labor  in  all  the  various  departments, 
as  is  always  possible  now  in  England. 

Manufacturers  who  desire  to  make  a  success  in  the  produc- 
tion of  enamel  brick  must  study  the  subject  thoroughly  so 
as  to  understand  fully  all  the  details  which  pertain  to  the  en- 
tire process,  and  in  addition  experienced  persons  must  be 
placed  in  each  of  the  various  departments  of  the  work. 

In  experimenting  with  the  various  enamels,  the  preparation 
of  which  the  writer  will  give  later,  do  not  be  discouraged  if  you 
do  not  achieve  satisfactory  results  in  the  first  trials.  From  50 
to  100  brick  for  experimenting  purposes  should  be  made  at 
one  time.  In  this  way  the  costs  of  the  experiments  will  not  be 
great,  and  by  repeating  the  experiments  several  times  better 
knowledge  of  the  business  will  gradually  be  gained,  and  this  is 
the  only  way  in  which  manufacturers  can  secure  desired  results. 

No  matter  how  great  may  be  a  man's  knowledge  of  brick  en- 
ameling, no  matter  how  great  his  practical  skill,  there  is  proba- 
bly not  living  any  person  who  can  locate  himself  in  any  brick 
works  and  there  successfully  manufacture  enamel  brick  of  sal- 
able quality  the  first  time  he  makes  the  effort  to  do  so.  But 
there  are  no  obstacles  pertaining  to  the  production  of  this  class 
of  wares  which  cannot  be  eventually  overcome  by  the  man  who 


406  BRICK,  TILES   AND   TERRA-COTTA. 

possesses  the  necessary  knowledge  and  skill.  There  may  be 
special  drawbacks  with  the  clay  from  which  the  brick  are  made. 
The  clay  may  contain  an  excess  of  silica,  in  which  case  the 
brick  would  increase  in  size  on  the  application  of  high  heats, 
and  would  contract  on  cooling,  thus  destroying  the  enamel  sur- 
faces. There  may  be  other  difficulties  in  the  way  of  successful 
results ;  but  no  matter  what  these  difficulties  are,  a  man  who 
thoroughly  understands  the  business  should  produce  in  his 
second  or  third  kiln  enamel  brick  of  salable  quality.  If  he  does 
not  accomplish  this,  there  is  but  little  hope  of  achieving  suc- 
cessful results  with  that  particular  man  in  charge.  One  glaze 
and  enamel,  and  the  same  method  of  procedure,  will  not  suit 
all  clays  and  all  places.  The  enamel  must  be  made  to  suit  the 
clay — if  the  clay  is  very  refractory  the  enamel  must  also  be 
hard  to  fuse,  for  it  must  not  flux  when  the  brick  is  only  half 
burned. 

The  brick  and  the  enamel  must  both  shrink  in  the  same  de- 
gree, for  if  the  brick  has  a  greater  shrinkage  than  that  of  the 
enamel,  the  latter  will  fall  off;  and  if  the  enamel  has  a  greater 
degree  shrinkage  than  the  clay  body  to  which  it  is  attached, 
the  enamel  will  crack  crosswise. 

THE    CLAY. 

The  best  clay  for  the  manufacture  of  enameled  brick  is  a 
high-grade  fire  clay,  light-buff  in  color  and  plastic  when 
ground,  one  which  is  practically  free  from  iron,  and  which  will 
vitrify  at  a  medium-high  temperature,  and  have  a  shrinkage  of 
not  more  than  three-quarters  of  an  inch  to  the  foot. 

PREPARING    THE    CLAY. 

If  possible  the  fire-clay  should  be  weathered — the  longer  the 
exposure  the  better  will  be  the  brick. 

The  dry- pan  and  riddel  and  wet-mixing  pan  will  temper  the 
clay  finely  and  evenly  and  impart  to  it  a  more  desirable  consis- 
tency than  will  any  other  method  of  preparing  the  clay. 


THE    MANUFACTURE   OF   ENAMELED   BRICK.  407 

MAKING. 

Any  good  wire-cut  brick  machine  can  be  used  for  making 
the  brick,  provided  only  water  from  the  lubricating  die  is 
allowed  to  come  in  contact  with  the  clay  while  it  is  being 
moulded. 

In  England  nearly  all  brick  which  are  to  be  enameled  are 
made  by  hand. 

It  is  of  great  importance  that  the  size  of  the  mould  should  be 
such  that  when  a  proper  allowance  has  been  made  for  shrink- 
age, the  brick,  when  placed  in  the  press  box,  shall  fill  it  as 
uniformly  as  possible,  and  of  just  right  proportions  to  enter  the 
box  cleanly. 

In  employing  machinery,  care  must  be  exercised  in  order 
that  none  of  the  oil  used  for  lubricating  the  cutting  table  or 
rollers,  or  any  other  portion  of  the  mechanism  where  oil  is 
commonly  used,  is  communicated  to*  the  green  brick.  Brick 
containing  oil  cannot  be  successfully  enameled,  and  all  brick 
which  contain  grease  of  any  character  must  first  have  such 
grease  removed  from  their  surfaces  before  they  are  dipped. 

Paraffine  and  olive  oil  are  the  best  lubricants  to  be  used  on 
all  machinery  to  be  employed  for  the  making  or  pressing  of 
brick  which  are  to  be  enameled.  Such  lubricant  oils  as  are 
generally  used  for  brickmaking  machinery  must,  under  no  cir- 
cumstances, be  employed.  It  is  desirable  that  a  lubricating 
die,  whose  only  lubricant  is  water,  should  be  employed  with 
stiff  clay  machines  used  for  the  making  of  the  brick.  The 
brick  should  be  made  stiff  enough  so  that  when  they  come 
from  the  cutting  table  they  can  be  hacked  on  the  hot  floor 
seven  or  eight  courses  high,  and  they  should  be  allowed  to  so 
stand  without  any  further  hundling  until  the  steam  has  been 
dried  out  of  them.  One  great  trouble  with  brick  made  by 
machinery  is  that  sufficient  attention  is  not  paid  to  the  adjust- 
ment of  the  die  of  the  machine.  The  die  must  be  a  little 
smaller  than  the  mold-box  of  the  press,  otherwise  the  brick 
require  dumping  to  make  them  pass  free  and  clean  into  the 
press  box.  Another  trouble  with  machine-made  brick  is  that 


408  BRICK,  TILES   AND   TERRA-COTTA. 

sufficient  care  is  not  exercised  to  keep  them  free  from  finger 
and  thumb  marks,  and  from  other  defects  which  materially 
lessen  the  value  of  the  finished  product.  When  machinery  is 
under  the  management  of  careful  and  intelligent  men,  there  is 
no  reason  why  the  machine-made  brick  should  not  fully  equal 
those  made  by  hand.  If  made  by  hand  an  experienced 
moulder  must  be  assigned  to  the  work  and  brass  molds  only 
should  be  employed  ;  no  sand  must  ever  be  used — only  water 
to  make  the  brick  slip  clean  from  the  mold — the  molds  being 
dipped  in  the  water-tub  after  every  two  brick  are  made. 

The  brick  are  made  on  a  hot-floor  the  same  as  other  fire- 
brick. The  floor  upon  which  the  brick  are  placed  to  harden 
must  be  only  warm,  not  hot,  and  the  oft"  bearer  must  put  the 
brick  on  the  floor  very  carefully,  in  order  not  to  destroy  their 
perfect  shape.  Iron  plates,  however,  are  apt  to  oxidize,  and 
this  oxidation  becoming  incorporated  in  a  minute  quantity 
with  the  edge  of  the  brick  lying  on  the  plates,  has  a  tendency 
to  discolor  the  body  and  glaze,  causing  the  brick  to  look  very 
unsightly,  The  flat  sides  of  the  brick  are  usually  depressed — 
the  name  of  the  firm  manufacturing  the  brick  being  in  one  de- 
pression and  the  initials  in  the  other.  This  gives  the  mortar  a 
better  hold  and  also  makes  the  brick  easier  to  burn. 

THE   FLOOR. 

The  heating  of  a  brick-making  floor  is  one  of  great  import- 
ance, and  requires  most  careful  consideration  as  to  its  construc- 
ticfn.  How  many  floors  have  been  laid  on  most  costly  systems, 
only  to  be  removed  as  unsatisfactory,  or  have  required  endless 
repairs  to  keep  them  in  order,  and  in  case  of  steam  heating  to 
keep  them  steam  tight.  The  exhaust  steam  from  the  engine 
may  be  satisfactorily  utilized  to  heat  a  very  large  area.  It  is 
the  best  medium,  giving  more  uniform  heat  than  when  the  best 
system  of  flues  is  used ;  it  is  much  more  cleanly,  and  is  cheap. 
Where,  however,  "  live"  steam  from  the  boilers  must  be  used, 
requiring  additional  boiler  and  plant,  the  saving  is  not  so  much 
as  is  popularly  supposed,  and  excepting  under  a  strong  and 


THE   MANUFACTURE    OF   ENAMELED    BRICK.  409 

undivided  management,  it  is  difficult  to  insure  a  good  supply 
being  maintained  during  the  night. 

The  following  is  a  good  and  well-tested  system  in  present 
use.  To  prepare  the  ground  take  out  all  old  flues,  etc.,  if  any, 
to  the  depth  required,  about  two  feet ;  well  ram  the  soil  or  clay 
for  a  foundation  perfectly  solid  and  level ;  then  lay  6  in.  to  9 
in.  bed  of  concrete,  rough  towards  the  bottom  and  finer  towards 
the  face ;  and  finally  finish  with  a  thin  layer  of  good  cement  or 
lias  lime.  If  cement  is  used  of  a  high-class  quality,  it  may  be 
mixed  with  a  proportion  of  sand  to  reduce  the  cost;  but  the 
object  of  this  face  is  to  prevent  the  steam  and  hot  water  perco- 
lating through  the  concrete,  and  causing  loss  of  heat,  etc.  The 
bed  of  concrete  must  be  laid  with  a  small  fall  towards  the  drain 
on  the  side  furthest  from  the  steam  supply ;  the  drain  will  also 
have  a  fair  amount  of  fall  towards  a  central  well  and  discharge 
pipe.  There  should  be  provided  a  ^team  trap,  to  check  the 
too  ready  escape  of  the  steam. 

Now,  if  the  size  of  the  quarries  to  be  used  for  the  first  course  is 
24  in.  by  24  in.  by  2^  in.  or  3  in.  thick,  at  distances  of  19^  in. 
apart,  three  courses  of  brickwork  must  be  laid  in  open  chequer 
work,  leaving  about  six  inches  clear  at  the  steam  supply  end. 
Upon  these  courses  of  brickwork  the  first  course  of  quarries  is 
laid,  resting  2%  in.  each  end  on  the  brickwork.  On  top  of 
these  lay  a  second  course  of  quarries,  forming  the  floor  surface, 
bedded  in  pure  cement.  The  work  must  be  done  with  the 
greatest  care  to  ensure  a  steam-tight  and  damp-proof  floor 
when  laid,  all  joints  must  be  grouted  with  cement  until  quite 
full.  The  top  course  of  quarries  must  be  arranged  so  that  they 
break  joint  with  the  lower  course  in  both  directions ;  in  no  case 
must  the  joints  be  allowed  to  fall  upon  one  another.  The  top 
course  of  quarries  need  not  be  more  than  2  in.  thick ;  they 
must  be  thick  enough,  however,  to  insure  their  being  level  and 
straight,  and  it  will  be  found  necessary  to  use  two  sizes^ 
probably,  to  ensure  a  uniform  crossing  of  the  joints. 

It  is  of  great  importance  that  the  floor  surface  is  level  and 
free  from  hollows  at  the  joints  or  curved  quarries,  as  it  has  been 


410  BRICK,  TILES   AND   TERRA-COTTA. 

found  by  long  experience  that  a  twist  given  to  a  brick  by  being 
laid  on  an  uneven  floor  is  never  totally  eliminated  by  pressing, 
etc.,  and  still  exists  in  the  finished  brick.  It  is  therefore  advis- 
able, when  possible,  to  have  the  floor  quarries  of  such  a  size 
that  a  certain  number  of  brick  lie  on  each  without  crossing  the 
joints ;  thus  8  brick  can  be  laid  on  a  24  in.  by  24  in.  quarry. 
The  steam  supply  is  distributed  evenly  by  cast-iron  pipes, 
about  2y%  in.  diameter,  having  holes  drilled  in  them  on  one 
side,  one  of  which  is  central  between  each  of  the  rows  of 
chequered  brickwork.  This  is  supplied  with  steam  from  pipes 
carried  overhead  from  the  boilers  into  the  sheds,  and  then 
brought  down  to  the  floor  by  a  vertical  pipe;  3  in.  diameter 
will  be  quite  large  enough  for  any  section,  as  large  as  it  is  de- 
sirable that  they  should  be.  Each  supply  pipe  is  provided 
with  a  valve  to  regulate  the  admission  of  steam,  or  when  neces- 
sary to  cut  out  the  section  from  use. 

It  is  desirable  and  usual  to  lay  a  floor  of  this  description  in 
sections  of  from  thirty  to  fifty  feet  in  length,  each  section  hav- 
ing its  own  supply  pipe  and  valve  and  steam  trap  at  either  end, 
so  that  if  the  whole  be  not  required,  a  portion  may  be  shut  off, 
economizing  steam  and  fuel,  and  also  rendering  them  easier  of 
repair.  This  obviates  throwing  a  large  part  of  the  floor  idle, 
and  allows  each  section  to  be  graduated  in  heat  as  may  be  re- 
quired, so  that  too  large  a  quantity  of  brick  are  not  ready  for 
getting  up  at  once,  thus  causing  waste. 

Brick  laid  on  a  floor  of  this  class  in  regular  working  are 
ready  for  taking  up  in  about  twelve  hours  from  the  time  they 
have  been  made  during  the  day ;  but  the  more  slender  the  clay 
and  the  closer,  the  longer  must  be  the  time  allowed  for  drying. 
It  is  often  necessary  to  allow  them  forty-eight  hours  in  which 
to  stiffen.  Another  plan,  instead  of  the  concrete  foundation — 
cheaper,  and  having  much  to  recommend  it  at  works  where 
there  is  only  too  often  a  large  number  of  wasted,  unsalable 
brick,  but  not  so  efficient  in  preventing  the  percolation  of 
water — is  to  lay  a  course  of  brick,  fire  or  old  glazed,  which 
must  be  fairly  well  burnt,  on  their  edge  on  the  bed  of  well 


THE  MANUFACTURE  OF  ENAMELED  BRICK.      41  I 

rammed  clay.  They  must  then  be  carefully  grouted  with  any 
suitable  material,  and  after  the  brickwork  courses  are  laid, 
filled  in  between  with  a  thin  layer  of  cement.  This  system  is 
also  in  very  successful  use.  At  all  places  where  a  steam  floor 
comes  up  to  the  main  walls,  or  divisional  walls  of  buildings, 
the  building  must  be  faced  with  cement,  or  the  steam  and 
moisture  will  rise,  rotting  the  brickwork,  and  making  the  shed 
damp  and  look  very  unsightly. 

PRESSING. 

When  the  brick  have  remained  on  the  floor  a  sufficiently 
long  time  to  allow  them  to  become  hard  enough  to  handle 
without  marking  them,  they  should  be  carefully  taken  from  off 
the  floor  and  placed  in  a  cool  location  and  covered  over  with 
canvas  or  sacking  and  allowed  to  "  sammy,"  or  in  other  words 
to  come  to  an  even  state  of  stiffness,* which  will  require  about 
ten  or  twelve  hours. 

The  brick  can  be  pressed  in  any  of  the  approved  forms  of 
lever  fire-brick  presses  in  common  use  in  the  United  States,  or 
in  the  power  press  made  especially  for  this  purpose  by  the 
Frey  Sheckler  Co. 

In  England  the  screw  press  is  commonly  employed  for 
pressing  the  brick. 

Whatever  form  of  press  is  used,  care  must  be  exercised  that 
the  press-box,  cap  and  plunger  are  very  accurately  fitted,  in 
order  that  the  corners  and  the  arrises  of  the  brick  will  be  per- 
fectly formed  and  not  have  the  slightest  fringe  on  them. 

The  brick  when  in  proper  condition  for  burning  are  carried 
to  the  presses  usually  twenty  at  a  time ;  ten  brick  being  placed 
on  each  of  the  two  boards  which  form  the  top  of  the  wheel- 
barrow, which  barrow  is  provided  with  springs  which  prevent 
jar  and  injury  to  the  brick.  The  brick  are  taken  from  the 
boards  and  placed  on  the  table  adjoining  the  press.  Here  a 
man  takes  each  brick  and  rubs  the  palm  of  his  hand  gently 
over  the  -face  of  the  brick  which  is  to  be  enameled,  so  as  to 
free  it  from  all  particles  of  clay  and  grit.  This  man  then  gives 


412  BRICK,  TILES   AND   TERRA-COTTA. 

the  same  face  of  the  brick  a  light  tap  with  a  dresser,  and  next 
makes  the  face  of  the  brick  even  and  smooth  by  using  a  palette 
knife,  commonly  ten  inches  in  length. 

The  man  who  is  to  press  the  brick  takes  it  up  with  both  of 
his  hands  and  adjusts  the  brick  on  the  press,  keeping  the  face 
of  the  brick,  which  has  been  carefully  prepared  as  above  de- 
scribed, always  towards  him. 

In  order  that  the  face  of  the  brick  which  is  to  be  enameled 
may  not  come  in  contact  with  the  side  of  the  mold-box,  as  the 
lower  plunger  descends,  the  presser  should  be  careful  to  crowd 
the  brick  far  back  on  the  plunger  plate.  When  the  brick  has 
been  properly  pressed,  every  corner  and  arris  should  be  sharp 
and  clean  and  perfectly  formed. 

After  the  brick  have  been  pressed  they  are  carried  on  a  flat 
top  spring  barrow  above  described,  to  a  drying  room  which 
there  are  series  of  racks  arranged  in  rows  on  each  side  of  the 
walk,  about  five  feet  in  width  left  between  the  two  rows  of  racks. 
These  racks  which  are  built  of  wood  are  fitted  with  board 
shelves  placed  one  over  the  other,  eight  high,  with  six  inch 
spaces  between.  This  arrangement  of  rack  and  pallets  is  pro- 
vided to  receive  the  brick  in  order  that  they  may  properly  dry 
after  they  have  been  enameled. 

The  boards  forming  the  shelves  should  be  one  inch  thick  by 
eleven  inches  wide,  and  the  racks  can  be  any  length  which  will 
suit  the  room.  The  racks  should  be  divided  into  sections  to 
hold  fifteen  brick  on  edge.  In  order  to  prevent  the  marking  of 
the  brick  on  the  back  as  they  are  made  to  slide  on  the  boards, 
the  top  surfaces  of  the  boards  should  be  dressed. 

ENAMELING. 

When  the  brick  arrive  in  the  drying-room  from  the  press  the 
brick  are  carefully  taken  from  off  the  flat  barrow,  and  if  made 
by  a  wire-cut  machine,  it  is  necessary  to  polish  the  face  or  head 
to  which  the  enamel  is  to  be  applied  with  a  knife  in  order  to 
close  up  all  holes  or  cracks  on  the  surface. 

Brick  made  by  hand  are  only  brushed  over  the  parts  which 


THE    MANUFACTURE   OF   ENAMELED    BRICK. 


413 


are  to  be  enameled  with  a  soft  brush,  as  will  be  explained 
later. 

The  next  operation  consists  in  applying  with  a  soft  brush  a 
preparation  to  the  same  portion  of  the  brick  before  brushed. 

In  order,  however,  that  the  subject  so  far  as  it  pertains  to  the 
preparation  of  the  various  glazes,  "  bodies"  and  stains  may  be 
fully  understood,  the  writer  will  now  describe  their  composi- 
tion and  explain  the  manner  in  which  they  are  applied  to  the 
green  brick. 


GLAZE  No.  i. 
1 8      Ibs.  Feldspar. 
3)^    "    Cornwall  stone. 
2>£    "   Oxide  of  zinc. 
i%    "   Whiting. 
I         "    Plaster. 
Mix  for  use. 

GLAZE  No.  2. 
A  little  softer  than  No.  I. 
10      Ibs.  Feldspar. 
2.%    "    Cornwall  stone. 
1*4    "    Oxide  of  zinc. 
i>6    "   Flint. 
%    "    Lynn  sand. 
%    "    Carbonate  barytes. 
Mix  for  use. 

WHITE  BODY  No.  i. 
36      Ibs.  China  clay. 
10%    "    Ball  clay. 
6        "    Cornwall  stone. 
3        "    Whiting. 
1)4    "    Flint. 
1)4    "    Plaster. 
Mix  for  use. 

WHITE  BODY  No.  2. 

Not  quite  so  white  as  No.  i. 
12      Ibs.  China  clay. 
3)4    «    Ball  clay. 
3        "    Feldspar. 
I       "    Flint. 
Mix  for  use. 


WHITE  BODY  No.  3. 
This  is  to  be  used  with  colors  only. 
1 8      Ibs.  Ball  clay. 
1 6        "    China  clay, 
9        "   Cornwall  stone. 
6        "    Flint. 
3    $  "    Lynn  sand. 
Mix  for  use. 


BUFF  BODY. 

i8 

Ibs. 

Best  fire  clay. 

16 

« 

Ball  clay. 

16 

« 

China  clay. 

8 

« 

Flint. 

6 

H 

Cornwall  stone. 

Mix 

for  use. 

CREAM  BODY. 

28 

Ibs. 

Ball  clay. 

12 

« 

China  clay. 

6 

" 

Best  fire  clay. 

8 

M 

Flint. 

4> 

'       « 

Feldspar. 

Mix 

for  use. 

IVORY  BODY. 

8 

Ibs.  China  clay. 

6 

" 

Ball  clay. 

6 

« 

Flint. 

3 

u 

Feldspar. 

Mix 

for  use. 

BRICK,  TILES   AND   TERRA-COTTA. 


MAHOGANY-BROWN  STAIN. 
15      Ibs.  Chromate  of  iron. 
10        "    Manganese. 
4        "   Crocus  martis. 
4        "    Oxide  of  zinc. 
Fire  hard  and  grind. 

VANDYKE-BROWN  STAIN. 

3  Ibs.  Chromate  of  iron. 

1  "    Manganese. 

i^    "   Oxide  of  nickel. 
Fire  hard  and  grind. 

YELLOW-GREEN  STAIN. 
I2>£  Ibs.  Flint. 
S%    "   Whiting. 
8j^    "    Bichromate  of  potash. 

4  "   Fluor-spar. 
3}^    "    Red  lead. 
2%    "    Plaster. 

Fire  hard  and  grind. 

RED-BROWN  STAIN. 

4  Ibs.  Oxide  of  zinc. 
2%    "    Red  oxide  of  iron. 

2  "    Bichromate  of  potash. 
2        "    Flint. 

Fire  hard  and  grind. 

LIGHT-BLUE  STAIN. 

10      Ibs.  Oxide  of  cobalt. 
9        "    Cornwall  stone. 

1  "    Sulphate  of  barytes. 
Fire  hard  and  grind. 

ORANGE  STAIN. 

5  Ibs.  Alumina. 

2  "    Oxide  of  zinc. 

I        "    Bichromate  potash. 

%    "    Red  oxide  of  iron. 

Fire  hard  and  grind. 

TURQUOISE  STAIN. 

6  Ibs.  China  clay. 

6        "    Oxide  of  zinc. 
i%    "    Oxide  of  cobalt. 
%    "    Carbonate  of  soda. 
Fire  hard  and  grind. 


SAGE-GREEN  STAIN. 
2      Ibs.  Calcined  oxide  of  nickel. 
i         "    of  above  turquoise  stain. 
Mix  for  use. 

ROYAL-BLUE  STAIN. 
40      Ibs.  Alumina. 
10        "    Oxide  of  zinc. 
5        "    Oxide  of  cobalt. 

4  "    Lynn  sand. 

1  "    Carbonate  of  soda. 
Fire  hard  and  grind. 

BROWN  STAIN. 

2  Ibs.  Oxide  of  zinc. 

I         "    Bichromate  of  potash.. 
^2    "    Iron  scales. 
Fire  hard  and  grind. 

BLUE-GREEN  STAIN. 
8      Ibs.  Flint. 

5  "    Oxide  of  chrome. 
4 

3 

Fire  hard  and  grind. 


H    zinc. 
"      "    cobalt. 


DEEP-BLUE  STAIN, 

13  Ibs.  Oxide  of  zinc. 

3  "        "       "  cobalt. 

2  "    Common  soda. 
9  "    Flint. 

Fire  hard  and  grind. 

CELADON  STAIN. 
12      Ibs.  Flint. 

6        "    Bichromate  of  potash^ 
8        "    Oxide  of  zinc. 
%    "        "       "  cobalt. 
Fire  hard  and  grind. 

DRAB  STAIN. 
1 8      Ibs.  Flint. 

3  «    Whiting. 

6        "    Oxide  of  nickel. 
2        "        "      "  cobalt. 
I         "        «      "  chrome. 
Fire  hard  and  grind. 


THE  MANUFACTURE  OF  ENAMELED  BRICK. 


415 


GRASS-GREEN  STAIN. 
15      Ibs.  Flint. 
10        "   Borax. 
4        "    Common  soda. 
14        "    Oxide  of  chrome. 
10        "  "      zinc 

314    "  "      cobalt. 

Fire  hard  and  grind. 

OLIVE-GREEN  STAIN. 
2}£  Ibs.  Flint. 
i        "    Borax. 


l%  Ibs-  Oxide  of  chrome. 
I         "  "      zinc. 

Yz    "  "      cobalt. 

Fire  hard  and  grind. 

MAZARINE  BLUE. 

Dip  the  brick  just  as  if  you  wanted 
them  for  white  brick,  but  when  ready  for 
glazing  take  a  pint  of  glaze  and  one 
ounce  of  light  blue  stain,  mix  them  well 
together,  run  them  together  through  a 
lauro  and  then  dip  the  brick  in  this. 


FIRST  BODY  USED. 


This  is  called  Dip  No.  I  and  must  in  all  cases  be  used  first, 
whether  for  colors  or  white.  It  is  made  as  follows  :  y2  pound 
of  white  body,  j£  pound  of  same  clay  as  the  brick  are  made  of. 
To  mix  this  body  it  is  best  to  put  some  of  your  own  clay  into 
some  clean  cold  water,  pass  it  through  a  sieve  (or  brass  lauro)  ; 
brass  lauro  is  by  far  the  best,  and  must  have  60  holes  to  I 
square  inch ;  pass  it  once  through  this  lauro.  Then  it  requires 
to  be  passed  through  a  sieve  or  brass  lauro  with  80  holes  to  I 
square  inch  at  least  3  times;  then  take  say  10  quarts  of  this 
and  10  quarts  of  white  body,  either  No.  I  or  2,  but  in  no  case 
use  No.  3  for  this  dip ;  if  you  are  going  to  dip  white  brick  in 
No.  I  white  body,  use  No.  I  for  this  slip,  and  if  you  are  going 
to  dip  into  No.  2  white  body  use  No.  2  ;  if  you  are  going  to 
dip  into  both  of  these,  then  have  some  of  both  of  these  whites 
mixed  separate  with  clay.  But  if  you  are  going  to  dip  in  any 
of  the  colors,  then  use  white  body  No.  I  for  this  body  and 
white  body  No.  3  to  mix  with  the  colors,  or  you  can  use  white 
body  No.  I  with  the  colors  if  you  wish,  but  you  must  add  a 
little  of  Lynn  sand  to  it,  say  J^  pound  to  every  20  pounds  of 
the  other.  Before  mixing  the  clay  slip  and  white  body  to- 
gether, they  must  both  weigh  28^  ounces  to  a  pint.  This 
body  is  called  Dip  No.  i.  White  body  and  all  colors  are 
called  Dip  No.  2.  Glaze  is  called  Dip  No.  3. 


41 6  BRICK,  TILES   AND   TERRA-COTTA. 

INSTRUCTIONS. 

As  soon  as  the  brick  leave  the  press  take  a  very  soft  brush 
and  stroke  over  the  parts  about  to  be  enameled  to  remove  all  oil 
that  may  have  got  on  while  pressing  (use  paraffin  and  sweet  oil 
to  press  with)  ;  after  this  take  a  similar  soft  brush  (  a  very  soft 
hat  brush  is  the  kind  to  use)  and  dip  this  brush  into  Dip  No. 
i ;  this  is  the  receipt  given  made  of  one-half  of  your  own  clay 
and  one-half  of  white  body,  and  again  stroke  the  same  portion 
as  before  with  this  brush.  Then  dip  the  brick  itself  into  Dip 
No.  /,  then  let  them  stand  say  for  three  or  four  hours,  (but  not 
drying),  but  just  enough  to  take  the  moisture  from  the  slip  just 
put  on,  and  whilst  still  moist  (we  mean  the  brick)  dip  again,  this 
time  into  Dip  No.  2;  this  is  either  the  white  or  colors  (see  ex- 
planations) ;  then  let  the  brick  dry  slowly  but  thoroughly 
white  hard.  They  must  be  thoroughly  white  hard,  and  when 
quite  white  hard  they  are  ready  for  glazing.  Dip  No.  j;  but 
before  glazing  them  remove  all  dust,  etc.,  that  may  have  got  on 
whilst  drying,  and  also  before  dipping  them  in  the  glaze  after 
the  dust  is  removed  they  must  first  be  dipped  (the  enameled 
portion  only)  into  clean  cold  water  and  immediately  into  the 
glaze.  Do  not  allow  the  brick  to  stand  above  one  minute  after 
dipping  into  the  water  before  you  dip  them  into  the  glaze,  Dip 
No.  j.  They  are  first  dipped  into  the  water  to  stop  the  brick 
from  sucking  up  the  substance  from  the  glaze.  You  will  see 
by  this  that  they  must  be  immediately  dipped  in  the  glaze,  Dip 
No.  J,  after  being  dipped  into  the  water.  They  then  require 
the  edges  or  sides  to  be  brushed  with  a  wire  brush  (old  cast- 
off  from  wool  shearing  will  make  these  brushes)  and  are  then, 
after  being  dried  on  the  boards  above  described,  ready  for 
either  kiln  or  oven.  In  placing  them  in  the  kiln  or  oven  set 
them  face  to  face,  not  to  touch,  say  one- half  or  one  inch  apart, 
we  mean  the  faces  ;  the  sides  can  go  quite  close  together,  and  as 
far  as  possible  put  all  whites  facing  whites  and  each  color  fac- 
ing same  so  that  the  colors  will  not  cast  a  shade  on  each  other. 
In  firing  go  very  slow  for  the  first  twenty-six  or  thirty  hours, 
then  push  up  the  fires  gradually,  not  too  quick,  but  when  once 


THE    MANUFACTURE   OF   ENAMELED    BRICK.  417 

pushed  up  do  not  allow  the  fires  to  fall  back  again,  and  when 
the  glaze  has  commenced  to  run  they  require  about  six  hours 
gradual  firing  or  when  run  quite  smooth  about  three  more  fires 
to  make  them  bright  and  clear.  Do  not  allow  the  cool  air  to 
get  into  the  kiln  whilst  cooling,  or  it  will  cause  them  to  crack 
and  craze,  and  do  not  draw  the  brick  until  quite  cold. 

Before  any  of  the  slips  or  bodies,  glaze  included,  given  are  used 
they  must  be  mixed  with  clean  cold  water  and  passed  through 
a  lauro,  60  to  80  holes  to  one  square  inch,  at,  least  4  times,  and 
must  weigh  as  follows:  Dip  No.  I,  28^  ounces  to  I  pint;  Dip 
No.  2,  28^  ounces  to  I  pint,  whether  white  or  colors;  glaze, 
Dip  No.  3,  28^  ounces  to  I  pint  after  being  passed  through 
the  lauros.  When  all  the  brick  are  set  in  the  kiln  or  oven  they 
should  be  covered  up  at  the  top  to  stop  all  the  dirt  and  sulphur 
from  the  coal  getting  on  them  whilst  being  fired.  You  can  fire 
these  brick  in  either  up  or  down-draft  kilns,  but  must  protect 
them  as  much  as  possible  from  the  sulphur  and  dirt. 

EXPLANATIONS. 

The  2  glazes  given  are  both  transparent,  that  is  to  say,  will 
show  through  any  color,  but  to  avoid  being  out  it  is  best  to 
add  a  little  of  each  color  to  the  glaze,  when  dipping  colors,  say 
Y^  ounce  of  color  to  every  pint  of  glaze ;  of  course  you  will 
know  that  they  must  be  kept  separate  and  when  putting  them 
through  the  lauro  everything  must  be  perfectly  clean  and  clear 
from  any  other  color ;  for  everything  in  connection  with  glazed 
brick  all  must  be  kept  strictly  clean,  and  also  clean  cold  water 
used.  Where  we  say  mix  for  use,  we  mean  they  must  be  put  in 
either  tubs  or  boxes  water-tight,  well  mixed  together,  then  put 
clean  cold  water  with  them,  mix  well  up  again,  then  run  or  put 
through  the  lauro  as  per  dip  No.  I  process,  once  through  the 
60  lauro  and  3  times  at  least  through  the  80  lauro ;  they  are 
then  ready  for  use.  The  buff  body  will  be  a  far  nicer  buff  if 
you  will  use  a  little  of  the  orange  stain,  after  it  has  been  fired 
and  ground;  say  put  I  pound  of  color  to  every  15  pounds 
of  the  buff  body,  but  it  must  be  passed  through  the  lauro 
27 


418  BRICK,  TILES    AND   TERRA-COTTA. 

after  this  stain  has  been  put  to  it.  By  fire  hard  and  grind, 
we  mean  weigh  the  mixings  as  given  in  each  receipt;  pass 
them  all  through  a  very  fine  sieve — we  don't  mean  a  lauror 
but  a  sieve  about  16  or  18  holes  to  the  inch;  mix  well  up 
together;  then  put  it  all  into  a  seggar  or  anything  biscuit 
(we  mean  by  biscuit  anything  that  has  not  been  glazed),  but 
you  should  first  put  a  coat  of  flint  inside  the  seggar  mixed 
with  water ;  this  will  prevent  the  color  or  rather  stain  from 
sticking  to  the  seggar,  etc.  Then  put  the  seggar  with  the  stain 
in  the  hottest  place  in  your  brick  kiln  and  fire  it;  when  it  is 
fired  you  will  find  the  flint  and  perhaps  the  seggar  stick  to  it; 
it  must  all  be  chipped  from  the  color ;  it  then  requires  grind- 
ing; you  should  have  a  color  pan  for  this  purpose,  but  if  you 
will  send  it  to  the  potters  they  can  grind  it  for  you,  as  they  must 
have  color  pans.  If  it  is  like  cinders  or  clinkers  when  it  comes 
out  of  the  kiln,  do  not  throw  it  away,  for  it  is  as  it  should  be, 
but  some  of  the  colors  will  not  go  like  this ;  orange  will  not,  no 
matter  what  heat  you  go  to.  After  it  is  ground  it  wants  drying 
in  biscuit  basins  or  anything  that  is  biscuit,  then  run  through  a 
very  fine  sieve ;  the  finer  the  better,  and  it  is  then  ready  for  use. 
You  then  take — for  instance  we  say  grass-green — you  will  take 
one  ounce  of  grass-green  stain  to  every  ten  ounces  of  white 
body  No.  3,  mix  them  well  together,  put  some  clean  cold  water 
with  them,  pass  them  through  a  sixty  lauro  once  and  through 
an  eighty  lauro  three  times,  make  it  to  weigh  28^  ounces  to  a 
pint,  and  it  is  then  ready  to  be  used  as  Dip  No.  2,  You  treat 
all  the  colors  in  this  way.  For  turquoise,  sage-green,  deep- 
blue,  royal-blue,  brown  and  grass-green,  use  one  ounce  of 
stain  to  every  ten  ounces  of  white  body  No.  3.  For  Van- 
dyke brown,  red-brown,  orange,  blue-green,  celadon,  yellow- 
green  and  olive-green,  use  one  ounce  or  one  pound  of  stain  to 
every  12  ounces  or  12  pounds  of  white  body  No.  3.  For  ma- 
hogany brown  use  i  ounce  or  I  pound  of  stain  to  every 
ounces  or  14  pounds  of  white  body  No.  3.  For  drab  use 
ounce  or  I  pound  of  stain  to  every  22  ounces  or  22  pounds 
white  body  No.  3.  For  light  blue  use  I  ounce  or  I  pound  of 


•: 

of 


THE    MANUFACTURE    OF   ENAMELED    BRICK.  419 

stain  to  every  80  ounces  or  80  pounds  of  white  body  No.  3. 
You  must  also  stain  the  different  glazes  as  we  have  before  men- 
tioned, viz.  J^  ounce  of  stain  to  every  pint  of  glaze,  but  light 
blue  is  excepted ;  you  must  use  I  ounce  of  light  blue  stain  to 
every  j£  gallon  of  glaze,  or  it  will  be  too  deep  a  color.  You 
will  see  we  mentioned  calcined  oxide  of  nickel  in  the  sage- 
green  receipt.  We  mean  by  calcined  that  it  must  be  fired. 
You  will  get  it  ready  calcined  and  ground  from  any  whole- 
sale druggist.  The  turquoise  stain  and  the  oxide  of  nickel 
must  both  be  calcined  and  ground  before  they  are  mixed  to- 
gether for  sage-green  stain ;  after  they  are  thus  mixed  you 
must  treat  them  just  as  the  other  colors,  viz. :  i  ounce  or  i 
pound  of  this  stain  to  every  10  ounces  or  10  pounds  of  white 
body  No.  3.  Be  very  careful  when  weighing  out  the  quantities 
that  you  obtain  the  correct  weights,  as  in  some  cases  J^  an 
ounce  will  throw  you  wrong  either  way.  You  cannot  be  too 
careful  in  weighing  them  out.  You  must  in  all  cases  put  dip 
No.  i  on  the  brick  first  (see  instructions)  ;  this  is  the  slip 
made  of  your  own  clay  and  white  body ;  then  the  white  body  is 
called  Dip  No.  2,  that  is  to  say  if  you  want  to  make  a  white 
brick.  For  the  second  dip,  dip  it  into  the  white  body,  but  it 
you  want  to  make  any  of  the  colors  (mazarine  blue  excepted) 
you  must  put  the  colored  body  on  instead  of  the  white,  and 
call  that  Dip  No.  2.  All  materials  used  to  make  the  stains 
you  can  obtain  from  any  wholesale  druggist ;  but  the  others, 
such  as  flint,  feldspar,  Cornwall  stone,  whiting,  plaster,  ball 
and  china  clays,  you  can  obtain  from  the  potters  or  from 
flint  mills,  or  wholesale  druggists  should  keep  them ;  the 
potters  should  keep  them,  as  they  are  obliged  to  use  all  the 
materials  which  we  have  mentioned  in  their  own  manufacture 
of  pots,  etc. 

SETTING. 

After  the  brick  have  been  enameled  and  are  perfectly  dry 
they  are  taken  from  the  boards  in  the  drying  room,  and  after 
being  placed  on  the  flat-top  spring  barrows,  care  being  ob- 
served that  the  brick  are  so  placed  on  the  barrows  as  not  to 


420  BRICK,  TILES   AND   TERRA-COTTA. 

touch  each  other,  they  are  then  carried  to  the  kiln  to  be  set. 
In  the  burning  of  enamel  brick  it  has  been  found  advantageous 
to  set  green  fire-brick  8  or  10  courses  high  over  the 
bottom  of  the  kiln,  as  well  as  to  set  the  green  fire  brick 
for  burning  around  the  sides  of  the  kiln  to  the  same 
height  as  it  is  intended  to  set  the  enamel  brick.  In  this  way  the 
first  flash  of  the  fires  comes  in  contact  with  the  ordinary  fire- 
brick, thus  shielding  the  enamel  brick.  Care  must  be  always 
taken  in  the  setting  of  enamel  brick  to  protect  their  enamel  faces 
from  the  action  of  the  flames  as  they  pass  through  the  kiln. 
The  brick  can  be  set  on  end,  but  the  faces  of  the  enamel  brick 
must  be  closed  in  and  protected  from  steam,  smoke  and  sul- 
phur during  the  firing  process,  and  the  brick  should  be  set  face 
to  face,  but  never  allowed  to  touch  each  other.  The  sides  of 
the  brick  can  be  placed  so  as  almost  to  touch,  and  as  has  also 
been  previously  stated,  the  brick  which  are  enameled  for  white 
should  face  each  other,  and  each  color  should  face  brick  of  the 
same  color,  thus  preventing  the  chemical  shading  of  the  vari- 
ous colors  which  would  be  likely  to  occur  under  the  action  of 
high  temperatures. 

Any  practical  man  who  has  had  experience  in  this  line  of 
work  will  find  no  difficulty  with  the  setting  of  the  brick. 

A  correspondent  who  recently  wrote  us  from  England  says : 
"The  way  I  would  set  the  enamel  brick  in  the  kiln  for  burning 
is  on  the  *  board,'  which  is  a  technical  term  in  England  for  a 
peculiar  manner  in  setting  brick,  and  means  to  stand  the  brick 
on  end  and  then  place  a  row  of  brick  on  the  top  of  them,  edge 
up.  By  this  means  the  face  of  the  enamel  brick  is  closed  in 
and  forms  a  nine-inch  wall.  This  wall  is  carried  up  to  a  height 
of  four  feet,  and  between  each  wall  there  is  left  a  space  of  about 
three  inches,  which  allows  the  fire  to  work  its  way  up  between 
the  wall  or  '  boards,'  and  prevents  the  smoke  or  sulphur  from 
the  coal  from  reaching  the  enamel  face  of  the  brick." 

KILNS. 
The  method  of  burning  enamel  brick  with  dead  heat  by  plac- 


THE   MANUFACTURE   OF   ENAMELED    BRICK.  421 

ing  them  in  seggars,  or  burning  them  in  muffled  kilns,  which 
was  practiced  a  few  years  since,  is  now  no  longer  in  vogue. 
The  great  cost  for  fuel  and  heavy  expenses  for  repairs  to  kilns 
forced  the  abandonment  of  this  method.  Under  no  circum- 
stances let  any  man  prevail  upon  you  to  erect  muffled  kilns  in 
which  to  burn  enamel  brick.  Such  kilns  are  not  necessary, 
and  the  brick  burned  in  them  are  in  no  way  an  improvement 
over  the  brick  burned  in  round  down-draft  kilns.  Square  kilns 
are  employed  in  some  parts  of  England  for  the  burning  of  these 
brick,  but  the  round-down-draft  kiln  has  the  preference.  In 
the  firing  of  enamel  brick  it  is  necessary  to  have  coal  which  is 
as  free  from  sulphur  as  it  is  possible  to  obtain  it. 

FIRING. 

The  steaming  or  water  smoking  of  ^enamel  brick  should  re- 
ceive the  closest  attention,  as,  without  great  care  being  exer- 
cised, it  is  possible  at  this  stage  of  the  work  to  ruin  an  entire 
kiln  of  brick.  While  the  enamel  brick  are  on  the  smooth 
boards  in  the  drying  room  after  being  dipped,  the  exterior  of 
the  brick  will  become  thoroughly  dry,  but  considerable  moist- 
ure will  still  be  present  in  the  centre  of  the  brick  when  they  are 
removed  from  the  boards  to  be  conveyed  to  the  kiln  for  firing. 
If  this  moisture  contained  in  the  interior  of  the  brick  should  be 
drawn  too  suddenly  to  the  surface  by  subjecting  the  brick  too 
quickly  to  a  high  heat,  the  enamel  surfaces  of  the  brick  will  be 
stained  with  a  black-bluish  streak  down  the  center,  thus  ren- 
dering the  wares  unsalable.  Other  defects  engendered  by  a 
too  quick  drying  off  of  the  moisture  will  result  in  flawed, 
cracked,  shaky  or  burst  brick. 

When  the  water-smoke  fires  are  started  in  the  kiln,  the  heat 
should  be  raised  very  slowly,  and  at  no  period  of  the  two 
nights  and  three  days  devoted  to  the  drying  of  the  brick  in  the 
kiln,  should  the  grate-bars  be  more  than  one-half  covered  with 
fire.  During  the  water-smoking  of  the  brick,  as  much  air  as 
possible  should  be  admitted  into  the  kiln,  and  if  the  fire  holes 
are  provided  with  doors,  these  doors  should  be  allowed  to 


422  BRICK,  TILES   AND   TERRA-COTTA. 

stand  wide  open.  After  this  preliminary  stage  is  passed  the 
intensity  of  the  heat  should  be  gradually  increased,  and  by  the 
third  day  all  the  brick  in  the  kiln  should  be  about  red  hot,  and 
when  once  under  full  fire  the  kiln  must  not  be  neglected  or 
allowed,  under  any  circumstances,  to  cool  down,  but  the  fires 
must  be  steadily  continued  until  the  glaze  has  run  bright.  The 
test-proofs  used  should  be  in  the  shape  of  a  cup  with  a  hole  in 
it  so  as  to  make  them  easy  to  draw  from  the  kiln.  This  test- 
proof,  both  inside  and  outside,  should  be  enameled  and  glazed. 
The  trial  pieces  should  be  drawn  out  from  each  end  or  side  of 
the  kiln  when  on  looking  through  the  peep  hole  into  the  inte- 
rior of  the  kiln  the  flame  will  appear  to  be  one  solid  white 
mass ;  none  of  the  brick  being  perceptible  through  the  white 
heat. 

An  examination  of  the  test-proofs  at  this  stage  of  the  burn- 
ing, the  proper  enamels,  having  been  used,  will  show  them  to 
have  a  sweaty  or  greasy  appearance,  thus  giving  evidence  that 
the  enamel  on  the  brick  is  in  the  incipient  stage  of  fluxing.  If 
the  trial  pieces  have  this  sweaty  or  greasy  look,  then  you  must 
force  your  fires  to  their  utmost,  increasing  the  heat  to  as  high 
a  temperature  as  is  possible,  and  in  the  meanwhile  drawing  out 
one  of  the  test-proofs  at  intervals  of  about  one  hour  to  learn 
precisely  the  progress  which  is  being  made  towards  the  com- 
plete fusion  of  the  enamel. 

Finally,  when  the  test-proof  has  been  drawn  having  a  glassy 
smoothness  of  surface,  the  time  is  now  arrived  when  firing  must 
stop.  All  the  fireplace  doors  and  every  part  of  the  kiln 
through  which  cold  air  drafts  could  find  an  entrance  into  the 
interior  should  be  carefully  daubed  so  as  to  make  the  kiln  per- 
fectly air-tight. 

COOLING. 

The  kiln  must  be  allowed  to  cool  very  gradually ;  no  aid 
should  be  given  to  the  cooling  process  by  opening  doors  or  in 
making  any  channels  through  which  the  air  on  the  outside  of 
the  kiln  can  enter  it.  The  chimney  must  be  depended  upon  to 


THE    MANUFACTURE    OF   ENAMELED    BRICK.  423 

cool  the  kiln,  all  dampers  leading  to  the  chimney  being  fully 
open  so  that  the  stack  can  do  this  work  unhampered.  This 
should  be  continued  until  the  beginning  of  the  sixth  day,  when 
the  holes  in  the  top  of  the  arch  of  the  kilns  can  be  opened, 
caution  being  first  exercised  that  all  dampers  in  flues  leading  to 
the  chimney  are  closed,  and  that  all  draughts  about  the  kiln  are 
stopped.  In  this  way  it  is  possible  to  draw  all  the  heat  from  the 
kiln  without  danger  of  injuring  the  enamel  brick.  The  wicket, 
however,  should  not  be  thrown  down  until  it  is  possible,  when 
putting  the  hand  through  the  holes  in  the  top  of  the  arch  of 
the  kiln,  to  pick  up  the  brick,  which  must  be  cool  enough  to 
handle  with  the  naked  hand.  By  following  these  directions  in 
the  cooling  of  the  brick,  "  air  cracks"  will  not  be  inflicted  upon 
the  brick,  which  lessen  their  market  value. 

The  sorting  of  the  brick  is  usually  in  three  classes,  and  has 
reference  to  the  condition  of  the  enamel  surfaces  of  the  wares. 
First  quality  brick  are  true  in  shape,  have  perfect  corners  and 
arrises,  and  the  enamel  surface  of  such  brick  must  have  neither 
flaws  nor  cracks.  Brick  having  cracks  either  visible  or  invis- 
ible or  blisters  form  the  second  quality  of  wares.  The  third 
class  of  brick  are  those  which  cannot  be  sold  for  second,  be- 
cause they  are  either  chipped  or  cracked,  and  the  manufacturer 
who  obtains  for  such  brick  the  price  of  ordinary  front  brick  is 
very  fortunate.  There  is  no  profit  in  manufacturing  either  sec- 
ond or  third  grade  enamel  brick.  The  manufacturer  who  can- 
not produce  at  least  seventy  five  per  cent,  first-class  enamel 
brick  will  find  his  profits  absorbed. 

The  enamels,  glazes  and  colors  used  in  the  manufacture  of 
these  brick  can  be  obtained  from  either  Messrs.  Harrison  & 
Son,  Hanley,  Staffordshire,  England,  or  C.  Bloor  &  Son,  Burs- 
lem,  England. 

ENAMELING    SLATE    WASTE    BRICK. 

Some  ten  years  ago,  when  first  the  manufacture  of  brick 
and  tiles  from  slate  waste  commenced  in  North  Wales,  the 
white-glazed  brick  was  successfully  produced  by  the  following 
process  and  recipes : 


424  BRICK,  TILES   AND   TERRA-COTTA. 

The  process  is  called  the  Biscuit-brick  process — that  is,  the 
firing  of  the  brick  only  slightly  at  first,  all  care  being  taken  in 
setting  and  drawing  the  bricks  so  as  not  to  damage  them  in  any 
way.  The  brick  need  to  be  fired  at  about  half  the  customary 
heat  for  the  first  fire ;  they  must  then  be  taken  to  the  dipping- 
house  to  be  dipped  in  the  body  and  glaze.  Having  everything 
in  readiness,  dip  the  part  required  to  be  glazed  in  clean  water ; 
you  then  pass  on  the  brick  to  the  next  hand,  whose  dip  will  be 
the  white  body ;  then  on  to  the  next  hand,  whose  dip  will  also 
be  the  white  body ;  again,  pass  on  the  brick  to  the  fourth  hand, 
whose  dip  will  be  the  glaze.  Allow  the  brick  to  dry  a  little ; 
then  take  a  knife  and  scrape  off  all  body  and  glaze  that  may 
have  run  over  the  side  of  the  brick.  The  brick  can  then  be  set 
in  the  kiln  to  be  fired  again.  The  slate  waste,  however,  is  a 
ticklish  material,  and  will  not  stand  a  hard  fire.  The  heat  it 
will  take  is  a  good  red  clay  heat ;  it  will  thus  be  seen  that  a 
down-draft  kiln  will  not  do  for  glazing  slate  waste.  It  must  be 
fired  in  a  kiln  where  all  the  flash-heat  can  be  kept  from  the 
brick — the  kiln  generally  used  is  the  Simmer  muffle-kiln.  The 
kiln  itself  when  set  with  brick  is  almost  a  box-kiln.  The  brick 
must  be  fired  gently  at  first,  and  when  on  full  fire  it  must  not 
be  neglected  or  allowed  to  sink  too  low.  The  firing  should  be 
continued  until  the  glaze  has  run  bright. 

The  following  are  the  recipes  of  body  and  white  glaze : — 

WHITE  BODY. 
74  lb.  china  clay,  1 ^%  lb.  stone, 

1 8  lb.  flint.  3>£  lb.  plaster. 

All  must  be  mixed  together  dry,  before  adding  water,  on 
account  of  the  plaster.  Dip  the  brick  at  30  oz.  to  the  pint 
slop,  and  pass  the  body  twice  through  a  fine  sieve. 

WHITE  GLAZE. 

19  lb.  feldspar,  %  lb.  plaster, 

6      lb.  stone,  2>£  lb.  best  flint  glass, 

i%  lb.  whiting,  12      oz.  white  lead. 

%  lb.  flint, 

Mix  as  above. 


CHAPTER  XII. 

THE   MANUFACTURE   OF   SEWER-PIPE. 

THE  clay  from  which  sewer-pipe  are  made  is  a  grade  of  fire- 
clay. Much  care  is  required  to  be  exercised  by  those  who 
select  the  clay  from  which  sewer-pipe  are  manufactured.  The 
coarse,  open,  non-plastic  clay  used  for  fire-brick  will  not 
answer  the  required  purpose.  Earthenware  pipe  of  this  char- 
acter require  that  the  clay  shall  be  plastic,  so  as  to  form  a  close 
homogeneous  body  similar  to  that  used  for  architectural  terra- 
cotta. It  is  also  desirable  that  the  clay  should  contain  a  large 
proportion  of  silica,  which  is  of  material  assistance  in  applying 
the  salt  glaze,  as  will  be  hereafter  explained. 

There  are  two  quite  well  marked  ways  of  making  sewer-pipe 
in  the  State  of  Ohio,  which  leads  to  their  classification  usually 
as  the  river  process  (that  used  in  the  Ohio  Valley  in  Jefferson 
county),  and  the  Akron  process  (used  at  Akron  and  Colum- 
bus). The  process  is  the  same  in  all  cases,  and  even  extends 
into  the  manufacture  of  fire-brick  as  far  as  the  grinding  and 
tempering  goes. 

When  the  clay  has  been  ground,  sifted  and  tempered,  it  is 
usually  elevated  by  a  belt  to  the  upper  story  of  the  works,  and 
deposited  in  a  bin  beside  the  top  of  the  sewer-pipe  press. 
All  sewer-pipe  machines  act  on  the  same  principle,  but  the 
mechanical  details  differ. 

The  pipe-press  consists  of  a  large  steam  cylinder,  upon  a  high 
iron  'frame ;  the  piston  runs  into  a  second  cylinder  of  less 
diameter  situated  beneath  it;  this  is  called  the  mud-drum  or 
mud-cylinder,  and  into  it  the  clay  to  be  pressed  is  introduced, 
and  from  its  lower  end  it  is  forced  out  as  pipe  by  the  pressure 
from  the  upper  or  steam  cylinder.  The  piston  at  the  upper 
limit  of  the  stroke  leaves  a  passage  into  the  inside  of  the  mud- 

(425) 


426  BRICK,  TILES   AND    TERRA-COTTA. 

drum  near  the  top,  which  is  closed  as  the  piston  moves  down 
further.  Into  this  opening  is  shoveled  the  tempered  clay.  It 
is  tempered  so  dry  that  it  may  be  shoveled  with  perfect  ease, 
and  it  has  no  tendency  to  stick  together  by  contact  alone, 
though  it  does  so  readily  by  pressure.  The  cylinder  being 
filled  with  clay,  the  piston  is  given  steam  and  moves  down 
slowly,  consolidating  the  clay  and  expressing  the  inclosed  air 
through  small  holes  in  the  piston-head  and  the  cylinder  bot- 
tom. When,  through  these  holes,  the  clay  begins  to  issue,  the 
pressman  knows  that  the  clay  has  filled  the  shape  of  the  cavity 
perfectly ;  and  as  the  bottom  is  a  movable  one,  it  is  loosened 
and  dropped  upon  a  balanced  platform  close  beneath  it.  This 
platform  under  the  weight  of  the  cylinder  head,  which  is  so 
shaped  as  to  form  the  pipe,  is  just  counter-balanced,  and  by 
any  pressure  can  be  moved  up  or  down,  carrying  the  socket 
shaper  on  its  top.  The  bottom  being  pushed  out  of  the  way, 
continued  pressure  from  above  causes  the  pipe  to  issue. 
When  enough  has  come  out,  it  is  cut  off  by  a  rotary  knife  from 
the  inside,  and  the  separated  length  of  pipe  is  carried  away 
either  on  a  cart  or  in  the  hands.  It  is  next  sponged  and  pared, 
to  smooth  it.  The  pipe  is  shaped  by  being  forced  ou^;  between 
the  walls  of  the  mud-drum  and  a  conical  core  which  is  sus- 
pended from  higher  up  in  the  drum.  This  cone  parts  the  clay 
evenly  on  all  sides,  and  causes  it  to  leave  the  press  in  an  even, 
regular  shape  and  thickness.  The  dimensions  of  the  presses 
used  are  various ;  the  Pittsburgh  press  at  Walker's  has  a  steam 
cylinder  44  inches  in  diameter,  and  23  inches  of  mud-drum. 
The  ordinary  diameter  is  from  35  to  36  inches,  and  about  18- 
inch  mud-drum. 

The  river  works  make  this  pipe  just  as  easily  as  they  do  the 
thinner  kinds,  and  they  claim  an  advantage  here  over  "their 
competitors  who  make  no  thick  pipe. 

The  differences  in  the  manufacture  of  pipe  in  the  Akron  and 
Columbus  district  from  the  river  process  begin  in  the  material 
employed.  The  grinding  machinery  of  the  Akron  district  con- 
sist of  the  machines  called  tracers.  The  tracer  is  an  excellent 


THE   MANUFACTURE   OF    SEWER-PIPE.  427 

machine  for  grinding  a  true  clay  of  a  sandy  or  plastic  nature, 
and  though  its  work  in  shale  is  successful,  yet  it  seems  as  if 
the  heavy  wet  mill  of  a  fire-brick  works  could  not  fail  to  be 
better.  It  would  at  any  rate  grind  much  more  in  the  same 
time  than  the  tracer,  if  it  did  not  grind  it  any  better.  The  frac- 
ture of  an  Akron  made  sewer-pipe  shows  frequently  small 
pieces  of  shale  which  have  escaped  the  wheels,  and  in  burning, 
these  pieces  usually  shrink  away  from  the  bond  clay  so  as  to 
make  a  loose  spot  in  the  pipe,  and  they  are  consequently 
weakening  in  their  effect. 

There  is  in  use  among  railroads  and  such  companies  a  kind 
of  pipe  which  is  especially  fitted  for  their  purposes.  It  is  called 
among  manufacturers  the  Cincinnati  Standard,  and  the  point  of 
difference  between  it  and  the  ordinary  pipe  in  the  market  is  in 
the  thickness  of  the  shell,  making  a  24-inch  pipe  2  inches  thick 
instead  of  I  ^  inches,  as  usual.  The  gang  necessary  to  run  a 
press  are:  1st,  one  man  to  fill  the  mud-cylinder;  2d,  one  en- 
gineer; 3d,  one  man  to  cut  the  pipe  and  help  handle  the  pipe; 
4th,  one  man  to  manipulate  the  socket  shaper;  5th,  from  one 
to  three  men  to  carry  off  the  pipe.  At  one  of  the  Eliottsville 
works,  a  press  is  in  use  having  two  mud-drums  parallel,  which 
are  filled  and  pressed  alternately,  so  that  the  press  may  work 
constantly  instead  of  filling,  pressing,  and  waiting  to  refill. 
The  drums  are  shifted  backward  and  forward  by  a  horizontal 
cylinder  to  one  side.  The  capacity  of  a  press  varies  with  the 
kind  of  clay  used,  the  size  of  pipe  made,  and  many  other  con- 
ditions, but  in  normal  working,  will  not  vary  far  from  these 
figures;  36-inch  press,  making  6-inch  pipe,  3,000  feet  a  day; 
12-inch  pipe,  1,000  feet  daily;  15 -inch  pipe,  800  feet;  1 8-inch 
pipe,  650  feet;  2O-inch  and  24-inch  pipe,  about  500  feet  daily. 

The  heat  used  in  sewer-pipe  burning  is  only  that  necessary 
to  get  a  good  salt  glaze ;  about  one  barrel  of  salt  to  a  kiln  is 
required.  Coal  is  the  fuel  invariably  used. 

The  process  of  glazing  with  salt  is  of  ancient  origin,  and  it 
consists  in  throwing  the  salt  into  the  kiln  towards  the  end  of 
the  firing,  and  just  before  the  highest  heat  is  obtained. 


428  BRICK,  TILES   AND   TERRA-COTTA. 

Salt  that  has  been  used  for  pickling  can  be  employed,  as 
it  is  not  requisite  that  it  should  be  pure. 

The  fires  should  be  properly  managed,  and  at  the  right  tem- 
perature, in  a  closed  kiln  or  oven ;  the  salt  is  thrown  uniformly 
through  the  holes  at  the  top  of  the  kiln.  Small,  light  scoop- 
shovels  are  best  for  this  purpose.  The  quantity  of  salt  neces- 
sary for  a  moderate-sized  oven  is  150  to  160  pounds.  About 
one-half  the  quantity  of  salt  having  been  thrown  into  the  oven, 
the  fire  is  momentarily  increased,  then  reduced,  and  a  few 
specimens  of  clay  burned  with  the  pipes  are  examined,  for  the 
purpose  of  testing  the  glaze.  The  remainder  of  the  salt  is  then 
thrown  in,  part  at  the  top  of  the  kiln,  and  part  regularly  over 
the  top  of  the  fire. 

The  temperature  of  the  kiln  is  so  high  at  the  "  burning  off," 
or  end  of  the  firing,  that  the  volatile  salt  is  at  once  converted 
into  vapor,  which  intimately  surrounds  the  pipes  in  the  kiln, 
and  there  is  consequently  a  reaction  of  the  vapor  on  the  silica 
of  the  clay  bodies. 

The  agent  which  promotes  the  reaction  of  the  silica  and  com- 
mon salt  is  the  aqueous  vapor  which  is  always  present  in  the 
flames  of  the  furnace.  The  oxygen  of  the  water  produces  soda 
with  the  sodium  of  the  common  salt,  while  the  hydrogen  com- 
bines with  the  chlorine,  and  is  evolved  as  hydrochloric  acid. 
The  soda  then  enters  into  combination  with  the  silica  and  forms 
the  glaze. 

The  glaze  produced  upon  the  earthenware  pipes  in  the  man- 
ner described  is  consequently  a  soda-glass,  and  forms  a  very 
thin  film  or  coating  upon  the  material.  It  is  of  course  manifest 
that  the  greater  the  quantity  of  silica  a  clay  contains  the  more 
readily  will  it  decompose  salt,  and  the  more  lustrous  will  be  the 
glaze  produced.  When  it  is  desired  to  secure  the  brown  color 
so  .common  on  drain-pipes,  it  is  communicated  to  the  glaze  by 
throwing  such  substances  as  birch  bark  into  the  fire  during  the 
glazing  process,  and  the  larger  volume  of  smoke  thus  evolved 
produces  the  desired  effect.  It  sometimes  happens  that  the 
ware  in  some  portions  of  the  kiln  becomes  covered  with  salt,  a 
part  of  which  then  appears  as  an  efflorescence. 


THE    MANUFACTURE   OF   SEWER-PIPE.  429 

After  the  kiln  has  been  properly  fired  all  the  doors  and  open- 
ings are  carefully  daubed  around  with  a  mixture  of  sand  and 
clay,  a  few  air-holes  in  the  furnace-doors  not  exposed  to  the 
wind  being  allowed  to  go  unplugged  for  a  few  hours,  and  after 
two  or  three  days  the  burned  and  vitrified  sewer-pipe  is  ready 
to  be  removed  and  shipped  to  market. 

The  finished  sewer-pipe  are  stacked  up  in  piles  ready 
for  sale.  The  fittings  which  go  with  the  pipe,  such  as 
curves,  elbows,  S-traps,  T-pieces,  X,  Y  and  U-pieces,  etc.,  are 
made  for  the  different  sizes  of  pipes ;  they  are  separately 
moulded  and  are  more  expensive  than  the  lengths  of  pipe,  as 
they  are  made  mostly  by  hand  in  plaster  molds,  and  all  the 
other  special  shapes.  The  "river  pipe"  manufactured  in  Ohio 
are  made  from  a  homogeneous  clay  ;  i.  e.t  the  clay  by  the  nature 
of  the  preparatory  steps,  is  reduced  J:o  a  fine,  even  state  of 
division,  and  by  the  character  of  the  tempering  plant  is  made 
into  a  perfectly  uniform  paste.  And  as  it  enters  the  pressing 
chamber  in  a  comparatively  fine  state,  the  force  which  com- 
presses it  does  not  make  the  lines  of  demarkation  between  the 
particles  which  composed  the  mass  apparent,  as  it  would  if  the 
clay  were  not  as  soft  as  it  is,  and  as  finely  divided.  So  when 
a  piece  of  river  pipe  is  broken  its  fracture  shows  an  even,  fine- 
grained structure,  not  so  fine  as  stone-ware,  but  very  similar 
and  varying  from  a  buff  to  a  grayish-blue.  This  latter  is  the 
best  tint  to  get,  as  it  insures  the  combination  of  whatever  im- 
purity the  clay  contains  with  the  free  sand,  and  development  of 
the  best  qualities  of  the  clay.  The  use  of  salt  makes  the  color 
a  necessity,  as  a  rule,  for  the  combination  of  iron  always  begins 
before  the  glazing  by  salt  vapor  does.  The  strength  that  these 
pipe  have  is  far  in  advance  of  any  other  Ohio  pipe,  as  the 
structure,  seen  on  the  fracture,  would  show.  The  degree  of 
heat  which  the  clay  will  stand  without  injurious  effects  is  far 
above  the  glazing  heat  of  the  pipe,  and  the  only  precaution  in 
the  burning  to  be  observed  is  to  secure  enough  heat  with  no 
close  limit  on  the  side  of  excess.  The  iron  found  in  these  Kit- 
tanning  clays  is  present  in  small  grains,  which,  under  the  action 


430  BRICK,  TILES    AND   TERRA-COTTA. 

of  the  salt  glaze,  make  unsightly  black  blisters  and  holes  in  the 
surface,  though  in  no  degree  injuring  the  utility  of  the  ware. 
This  feature  has  hitherto  much  injured  its  popularity.  It  is 
beginning  to  receive  more  credit  than  ever  before,  because  its 
superior  strength  and  durability  are  now  being  recognized. 
The  color  of  the  river  pipe  is  light-red ;  in  spots,  where  the 
heat  did  not  get  access  to  it,  it  is  light  buff,  and  in  over-burnt 
portions  a  dark-red  color,  which  has  not  a  pleasing  effect. 
The  even,  beautiful  red  color  of  the  Akron  and  Columbus  pipe 
have  been  the  secrets  which  have  given  them  their  popularity 
above  other  kinds,  but  experience  teaches  that  the  color  is  not 
essential  to  the  best  results.  The  river  pipe,  on  account  of 
their  light,  red  color,  and  mottled,  spotted  appearance,  have 
not  had  popularity  in  the  West,  particularly  in  Chicago,  the 
greatest  of  all  markets,  but  they  are  constantly  gaining  ground 
there. 

The  grinding  takes  from  forty-five  to  fifty  minutes,  and  about 
1,200  pounds  constitute  a  charge;  the  water  used  is  added  by 
the  bucketful,  and  the  clay  is  tempered  very  stiff.  In  many 
works  they  use  only  two-thirds  as  many  machines  as  necessary, 
and  run  part  of  their  plant  all  night  to  get  the  necessary  clay 
for  the  next  day's  campaign.  The  ground  clay  is  shoveled  into 
a  squeezer  either  of  the  screw  or  piston  type,  and  it  is  concen- 
trated into  a  long  compact  cylinder  about  6  inches  or  8  inches 
in  diameter.  This  is  cut  up  in  lengths  of  about  15  pounds 
weight,  and  is  fed  to  the  machine  in  that  shape.  From  this 
results  the  worst  trouble  of  the  Akron  pipe ;  the  stiffness  of 
the  clay  and  the  large,  well-compressed  wads  in  which  it  is  fed, 
act  together  in  keeping  the  clay  from  uniting  to  a  homogene- 
ous mass.  Even  under  the  powerful  pressure  of  the  machine, 
the  lines  of  demarkation  between  the  different  pieces  going  to 
make  up  a  pipe  are  plainly  to  be  seen  on  the  fracture  of  a 
burned  pipe.  They  are  arranged  in  circles  concentric  to  the 
outside  of  the  pipe,  and  often  a  crack  of  one-sixteenth  of  an 
inch  separates  the  layers  of  the  clay.  This  is  all  developed  on 
burning,  but  is  not  visible  before  to  any  such  degree.  The 


THE   MANUFACTURE   OF   SEWER-PIPE.  431 

working  of  the  clay  is  admirable.  It  issues  from  the  press  as 
smooth  as  if  moulded  with  oil,  and  the  sockets  are  beautifully 
true  and  correct.  The  drying,  setting  and  burning  need  no 
special  attention.  The  kilns  used  are  the  same  as  are  used  for 
burning  stone-ware ;  they  are  oblong,  end-fired  down-drafts, 
about  30  to  35  feet  long,  and  15  to  20  feet  wide,  with  an  ave- 
rage capacity  of  about  40  tons.  The  burning  takes  six  days. 

The  character  of  Akron  sewer-pipe-ware  has  already  been, 
hinted  at  in  the  description  of  the  river  pipe.  It  is  a  smooth, 
handsome  ware,  well-shaped,  of  a  beautiful  dark  red-brown 
color,  and  remarkably  uniform.  On  its  fracture  it  shows  the  red 
color  of  a  brick  or  even  a  darker  red,  which  demonstrates  the 
presence  of  iron  in  that  peculiar  state  so  hard  to  define,  which 
is  necessary  to  the  development  of  the  high  color;  the  per 
cent,  of  iron  must  be  high,  yet  but  little  of  that  offensive  blotch- 
ing seen  on  the  river-made  ware  can  Be  noticed.  The  weaken- 
ing of  the  whole  structure  by  the  concentric  cracks  due  to  the 
pressing  is  the  worst  fault  of  the  pipe. 

As  to  the  inability  of  the  Akron  works  to  make  the  Cincin- 
nati Standard  pipe,  this  is  to  be  said  :  The  increase  of  thickness 
of  their  pipe,  with  the  same  amount  of  drying  which  they  now 
give  it,  is  liable  to  cause  large  flakes  to  spall  off  from  the  sides 
of  the  pipe  when  heated  in  the  kiln.  With  a  longer  and  hotter 
drying  they  could  make  these  thick  pipe,  but  as  their  capacity 
is  used  to  the  fullest  rate  now,  they  are  under  no  necessity  to 
begin  its  manufacture.  One  point  where  they  hold  a  decided 
advantage  over  the  river  district,  is  the  use  of  the  patent  device 
for  making  curves,  elbows,  S's  and  traps.  They  can  control 
the  position  of  the  core  inside  the  mud-drums  by  a  lever,  and 
by  moving  it  so  as  to  make  one  aperture  smaller  than  the 
other,  the  clay  issues  the  fastest  on  the  thinnest  side  and  the 
pipe  takes  a  curve  shape.  Also  by  using  a  softer  clay  on  one 
side  than  the  other,  the  softest  part  issues  faster  and  the  pipe 
curves.  The  movable  core  is  so  nicely  manufactured  that  such 
curves  as  the  letter  S,  and  the  stench  traps,  can  be  made  with- 
out help  from  the  hands.  This  is  a  patented  principle,  and  the 


432  BRICK,  TILES    AND   TERRA-COTTA. 

Akron  works  have  a  monopoly  on  it,  and  refuse  to  share  with 
other  parties. 

The  catalogues  and  circulars  of  the  Akron  manufacturers 
claim  that  they  sell  a  vitrified  pipe.  But  the  word  vitrified  has 
a  definite  signification.  It  would  require,  if  properly  applied, 
that  the  clay  should  have  been  fused  to  a  glass,  or  that  it 
should  have  undergone  incipient  fusion,  or  that  its  free  silica 
and  fluxing  impurities  should  have  been  made  to  combine. 
But  none  of  these  conditions  are  met.  The  fracture  of  the 
Akron  pipe  is  not  in  the  least  vitreous.  On  the  contrary,  par- 
ticles of  the  mass,  such  as  pieces  of  shale,  can  frequently  be 
seen  separate  and  distinct  from  the  body  clay.  The  color  also 
of  combined  oxide  of  iron  and  silica  is  dark,  running  from  blue 
to  black,  while  the  color  of  uncombined  oxide  of  iron  is  red ; 
the  color  of  the  Akron  pipe  is  red,  showing  that  the  impurities 
are  not  in  a  state  of  combination.  But  though  the  pipe  is  not 
vitrified,  it  is  probably  Better  than  if  it  were,  for  the  excess  of 
the  iron  in  the  clay  would  tend  to  make  it  brittle,  if  it  were  in 
real  combination.  In  other  words,  vitrification  would  present 
not  only  an  undesirable  but  a  dangerous  quality  in  the  sewer- 
pipe.  Judicious  experimentation  with  powdered  feldspar,  salt, 
potash  solution,  or  any  fluxing  agent  would  very  soon  establish 
the  practicability  and  test  the  advantage  of  making  the  vitrified 
pipe  throughout.  The  Akron,  Ohio,  sewer-pipe  have  as  wide  a 
distribution  as  any  other  similar  manufactured  product  in  Ohio  ; 
they  go  in  all  directions  and  in  all  quantities. 

Frederick  H.  Robinson,  C.  E.,  gives  the  following  description 
of  the  manufacture  of  sewer  pipe  by  the  Delaware  Terra  Cotta 
Co.,  of  Wilmington,  Del. : 

"  The  works  are  situated  on  Brandywine  Creek,  between 
Heald  and  Eleventh  streets,  and  close  to  the  Philadelphia,  Wil- 
mington and  Baltimore  Railroad.  They  are  equipped  for  the 
manufacture  of  all  the  standard  sizes  and  shapes  of  sewer  pipe, 
as  well  as  of  other  work  in  terra  cotta,  and  of  fire-brick. 

"The  material  of  which  the  pipes  are  made  is  composed  of 
three  ingredients — two  kinds  of  clay,  and  a  sand  and  clay 


THE    MANUFACTURE   OF   SEWER-PIPE.  433 

mixed.  The  first  is  a  very  strong  clay  obtained  from  brick 
yards  in  the  northeastern  part  of  the  city.  It  underlies  the 
clay  of  which  brick  are  made.  The  second  is  a  strong  clay 
containing  a  red  coloring  matter,  and  is  obtained  from  the 
south  side  of  the  Christiana  River  in  New  Castle  Hundred,  near 
the  bridge  on  which  the  Delaware  Railroad  crosses  the  Christ- 
iana. The  third  ingredient  is  a  material  composed  of  fire-clay 
and  sand,  and  is  obtained  on  the  Christiana  River  in  New  Cas- 
tle Hundred.  These  ingredients  are  mixed  in  the  proportion 
by  measurement  of  two  parts  of  the  strong  clay  first  mentioned, 
one  part  of  the  clay  containing  the  red  coloring  matter,  and 
one  part  of  the  fire-clay  and  sand.  Made  in  these  proportions 
the  mixture  is  placed  in  the  wet-pan,  where  water  is  added. 
The  wet-pan  is  a  shallow  circular  iron  pan,  in  which  the  clays 
are  crushed  and  mixed  by  two  iron  wheels,  following  each 
other  on  edge  around  the  pan,  driven  \>y  a  horizontal  axle  at- 
tached to  a  vertical  shaft.  This  pan  is  placed  on  the  ground 
floor. 

"After  the  materials  are  properly  mixed,  this  clay  is  turned 
by  a  suspended  shovel  into  the  buckets  of  the  elevator,  which 
are  attached  to  an  endless  band,  in  which  it  is  raised  to  the 
third  floor  of  the  building. 

"Projecting  from  the  third  floor  towards  the  second  is  the 
casting  which  contains  the  iron  mould  for  the  pipe.  Into  this 
the  clay  from  the  wet-pan  is  thrown,  and  an  iron  plunger, 
moved  by  the  piston  of  a  steam  cylinder,  which  piston  is  at- 
tached to  the  upper  end  of  the  plunger  rods,  descends  verti- 
cally, compressing  the  clay  in  the  mould  below. 

"After  the  clay  is  thoroughly  compressed  in  the  mould,  an 
iron  table  under  the  mould,  attached  to  the  upper  end  of  a 
piston  passing  below  the  second  floor,  and  forming,  as  it  were, 
the  bottom  for  the  mould,  descends  with  the  pipe  standing 
upon  it.  The  alternate  upward  and  downward  motions  of  the 
piston  which  moves  the  plunger,  and  the  piston  which  moves 
the  table,  are  controlled  by  the  operator  on  the  second  floor, 
where  the  pipes  are  removed  from  the  mould. 
27 


434  BRICK,  TILES   AND   TERRA-COTTA. 

"  Pipes  under  five  inches  in  diameter  are,  when  taken  from 
the  mould,  immediately  removed  to  another  part  of  the  second 
floor,  where  they  have  placed  in  them  a  wooden  frame  of  the 
proper  length,  to  which  their  ends  are  trimmed  off  and  then 
smoothed  with  leather.  As  those  over  five  inches  in  diameter 
come  from  the  mould,  they  immediately  have  their  spigot  ends 
trimmed  off,  and  are  then  taken  by  an  elevator  to  the  first  floor 
where  their  ends  are  finished  up.  These,  with  the  smaller  pipes 
from  the  second  floor,  are  placed  on  end  on  the  drying  floor  of 
the  first  story  of  the  building,  where  they  remain  from  three  to 
six  days,  when  they  are  ready  for  burning. 

''Branches  are  made  by  placing  the  branch  piece,  while 
damp,  upon  the  main  pipe,  and  then  trimming  and  shaping 
them. 

"Traps  are  formed  by  hand  in  plaster-of-Paris  moulds,  which 
are  made  in  halves,  dividing  lengthwise. 

"The  walls  of  the  kilns  are  of  brick  and  are  13  inches  in 
thickness.  The  kilns  are  circular,  the  largest  being,  inside,  22 
feet  in  diameter,  and  8  feet  high  to  the  square,  surrounded  by 
a  dome. 

"  The  kiln  is  filled  with  pipes  from  the  drying  floor,  placed 
on  end;  It  is  fired  from  eight  fire-places  at  equal  distances 
around  the  kiln.  Gas  coal  is  used.  Inside,  the  products  of 
combustion  pass  through  short  vertical  stacks  toward  the  top 
of  the  kiln,  whence  they  are  beaten  back  among  the  pipes,  and 
finally  escape  through  a  flue  built  around  the  kiln  near  the 
bottom,  and  pass  in  an  underground  flue  to  the  stack. 

"At  the  proper  stage  of  burning,  which  is  ascertained  by 
small  test  pieces  of  clay  which  may  be  drawn  and  examined, 
the  attendant  passes  three  times  around  the  kiln,  and  each  time 
throws  into  each  fire-place  a  shovelful  of  common  salt.  By  this 
the  pipes  are  glazed. 

"After  the  sealing  of  the  kiln  three  days  are  required  in 
which  to  fire  up  and  burn,  and  three  more  in  which  to  cool  off 
and  remove  the  pipes,  which  are  inspected  and  are  then  ready 
for  the  market." 


THE   MANUFACTURE    OF    SEWER-PIPE.  435 

MAKING  CURVED  EARTHENWARE  PIPES  OF  EQUAL  THICKNESS  ON  ALL  SIDES. 

The  curves,  elbows,  and  traps  for  sewer-pipe  are  now  also 
made  by  machines  especially  constructed  for  the  purpose, 
which  are  so  arranged  that  by  moving  a  plate  placed  over  the 
mouth  of  the  die  the  clay  can  be  made  to  issue  more  rapidly 
from  the  opened  side  than  from  the  other.  The  curve  is  formed 
in  the  pipe  toward  the  side  on  which  the  space  is  contracted^ 
By  sliding  the  plate  on  the  other  side,  the  pipe  will  curve  in  an 
opposite  direction,  and  by  a  succession  of  movements  of  the 
plates  any  desired  form  of  curve  or  trap  can  be  made. 

The  machine  shown  in  Figs.  136  to  138  is  the  invention  of 
Mr.  Horace  B.  Camp,  of  Cuyahoga  Falls,  Ohio,  and  relates  to 
the  formation  of  curves,  elbows,  and  traps.  • 

Fig.  136  represents  a  central  vertical  section  of  a  portion  of 
an  ordinary  cylinder  and  attachments  for  making  pipe  and  em- 
bodying this  invention. 

To  the  cylinder  A,  from  which  the  clay  is  pressed  to  form  the 
pipe,  by  a  piston  (not  shown),  is  bolted  a  cylinder  head  C, 
made  converging  to  facilitate  the  descent  of  the  clay.  To  the 
head  C  is  bolted  the  outside  hollow  die  D,  having  an  inside 
diameter  at  the  bottom  of  the  size  of  the  desired  pipe,  and 
within  which,  supported  centrally  by  means  of  the  rod  F,  is  the 
core  M,  having  an  outside  diameter  of  the  size  of  the  inside  of 
the  desired  pipe.  Between  the  die  D  and  head  C  is  a  chamber 
or  recess,  in  which  is  fitted  a  plate  P,  Fig.  136,  free  to  slide 
longitudinally  in  one  direction  at  right  angles  to  the  main 
cylinder  and  core,  and  moved  by  means  of  a  hinged  lever,  as 
will  appear  from  Fig.  138,  which  represents  a  transverse  section 
of  Fig.  136  at  the  bottom  of  the  plate  P,  looking  from  below. 
Through  the  plate  P  is  an  orifice  of  the  shape,  and  approxi- 
mately of  the  size,  of  the  pipe  to  be  made,  within  which  the 
mandrel  is  suspended,  and  having  the  edges  beveled  from  the 
upper  surface  outward.  When  the  plate  P  remains  so  that  the 
core  M  is  exactly  in  the  centre  of  the  orifice  therein,  the  clay 
descends  with  the  same  rapidity  on  all  sides  of  the  core,  and  is 
discharged  in  a  continuous  straight  pipe.  By  sliding  the  plate 


436 


BRICK,  TILES    AND   TERRA-COTTA. 


to  one  side,  the  space  5  between  the  edge  of  the  orifice  in  the 
plate  P  and  the  mandrel  is  lessened  on  one  side,  and  corres- 
pondingly increased  on  the  other.  The  result  of  this  is  that  the 
clay  descends  and  escapes  more  rapidly  on  the  opened  side  of 
the  mandrel  than  on  the  side  where  the  space  5  is  contracted, 
and  as  it  is  discharged  from  the  die  D,  it  curves  toward  the 


FIG.  138. 

side  on  which  the  space  is  contracted.  By  sliding  the  plate  to 
the  other  side,  the  pipe  will  curve  in  an  opposite  direction,  and 
by  a  succession  of  movements  of  the  plate,  any  desired  form  of 
curve  or  trap  can  be  made.  The  relative  positions  of  the  die 
D  and  core  M  remain  at  all  times  unchanged,  and  as  a  result 
the  pipe  is  of  equal  thickness  on  all  sides. 

The  principle  of  curving  such  pipes,  by  allowing  the  clay  to 
discharge  more  freely  on  the  one  side  of  an  annular  orifice  than 


THE   MANUFACTURE    OF    SEWER-PIPE.  437 

on  the  other,  is  not  new.  Nor  is  the  idea  new  of  making 
parts  of  a  pipe-machine  movable  at  the  will  of  the  operator 
while  the  pipe  is  issuing,  thereby  enabling  him  to  make  reverse 
or  other  compound  curves,  as  several  devices  have  been  in- 
vented and  patented  for  moving  either  the  die  D  or  core  M, 
while  the  pipe  is  forming.  But  all  these  devices  have  refer- 
ence to  a  change  in  the  annular  opening  between  the  core  M 
and  die  D  at  the  point  of  discharge,  and  herein  they  differ 
radically  from  this,  in  that  the  pipe  is  of  uneven  thickness  on 
different  sides. 

MACHINES    FOR    FORMING    SOCKETS    ON    CURVED    EARTHENWARE    PIPES. 

The  contrivances  employed  for  forming  sockets  on  curved 
earthenware  pipes  are  also  very  ingenious,  and  in  order  to  ex- 
plain the  machine  used  for  this  purpose  it  is  necessary  to  state 
that  ordinarily  to  form  such  sockets  on  sections  of  straight  pipe, 
the  outer  die  is  prolonged  beyond  the  point  of  discharge  of 
such  length  and  inside  shape  as  to  form  the  outside  of  the  de- 
sired socket.  When,  however,  the  pipe  curves  as  it  issues  from 
the  orifice,  this  device  is  impossible,  as  the  issuing  pipe  en- 
counters the  edge  of  this  socket-die  and  is  destroyed.  In  or- 
der to  obviate  this  difficulty  the  socket-die  is  constructed 
separately  from  the  other  parts  of  the  machine,  in  the  form  of 
a  ring,  divided  into  two  parts,  so  as  to  permit  of  its  being 
removed.  By  means  of  a  lever  this  ring  is  firmly  held  in  place 
until  the  socket  is  formed,  when  by  a  combination  of  arms  and 
links  the  ring  is  opened  automatically,  and  the  socket  having 
been  formed,  the  curving  of  the  pipe  is  proceeded  with. 

The  machine  shown  in  Figs.  139  to  145,  is  also  the  inven- 
tion of  Mr.  Horace  C.  Camp,  of  Cuyahoga  Falls,  Ohio. 

The  invention  has  relation  to  that  class  of  machinery  for 
making  pipes  of  clay,  or  other  plastic  material,  by  pressing  it 
through  annular  orifice  between  an  outside  die  and  an  inside 
core,  and  its  object  is  to  form  sockets  on  the  end  of  sections  of 
such  pipe  when  the  pipe  is  caused  to  curve  as  it  issues  from  the 
orifice. 


438  BRICK,  TILES   AND   TERRA-COTTA. 

In  order  to  present  the  distinctive  features  of  the  invention 
it  is  proper  to  state  that  ordinarily  to  form  such  sockets  on  sec- 
tions of  straight  pipe,  the  outer  die  is  prolonged  beyond  the 
point  of  discharge  of  such  length  and  inside  shape  as  to  form 
the  outside  of  the  desired  socket.  When,  however,  the  pipe 
curves  as  it  issues  from  the  orifice,  this  device  is  impossible,  as 
the  issuing  pipe  encounters  the  edge  of  this  socket  die  and  is 
destroyed.  To  obviate  this  difficulty,  Camp  constructs  the 
socket-die  separate  from  the  other  parts  of  the  machine,  in  the 
form  of  a  ring,  divided  into  two  parts,  so  as  to  permit  of  its 
being  removed  ;  and  the  first  part  of  this  invention  relates  to 
the  method  of  holding  this  severed  ring  firmly  in  place  until 
the  socket  is  formed,  which  consists  in  fitting  its  upper  edge 
into  a  groove  in  the  lower  face  of  the  outside  die,  and  its  lower 
edge  into  a  groove  in  a  flange  projecting  from  the  base  of  the 
die,  which  forms  the  inside  of  the  socket ;  and  the  second  part 
of  the  invention  relates  to  a  combination  of  arms  and  links  for 
manipulating  the  parts  of  the  ring. 

For  the  purposes  of  this  description,  we  adopt  the  following 
nomenclature : 

That  part  of  the  pipe-press  which  forms  the  outside  of  the 
annular  orifice  through  which  the  pipe  issues — the  outside  die. 
The  piece  suspended  centrally  within  this,  and  which  forms 
the  bore  of  the  pipe — the  core.  The  die  which  forms  the  in- 
side of  the  socket — the  lower  die ;  and  the  severed  ring  which 
is  interposed  between  the  outside  die-  and  the  flange  of  the 
lower  die,  and  forms  the  outside  of  the  socket — the  ring. 

Figure  139  is  a  sectional  view  of  a  portion  of  the  lower  part 
of  a  pipe  press,  wherein  A  is  the  outside  die,  and  B  the  core; 
the  outside  die  A  having  a  groove  5  in  its  lower  face  to  receive 
the  upper  edge  of  the  ring. 

Fig.  140  is  a  central  section  of  the  ring  C,  divided  in  half  at 
a  line  a  (a  plan  of  which  is  shown  in  Fig.  145),  and  having  its 
upper  edge  turned  to  accurately  fit  in  the  groove  S,  in  the  out- 
side die  At  and  its  lower  edge  fitted  in  the  same  manner  for 
the  groove  R  of  the  flange  of  the  lower  die  D. 


THE   MANUFACTURE    OF   SEWER-PIPE. 


439 


Fig.  141  is  a  side  view  of  one  of  the  hooks  H. 

Fig.  143  is  a  plan,  and  Fig.  142  a  section  of  the  line  x  x  of 
the  lower  die  D.  Upon  alternate  sides  of  the  flange  of  this 
die  are  two  lugs  d  d,  which  lock  into  hooks  H  H  attached  to 
the  outside  die  A,  and  hold  the  several  parts  together  while 
the  socket  is  formed. 

In  operation,  the  lower  die  D,  by  means  of  the  collar  E  pro- 
jecting from  its  base,  rests  upon  a  following  rod  (not  shown), 
which  moves  in  the  line  of  the  axis  of  the  press.  The  ring  C 
is  then  placed  thereon,  with  its  lower  edge  fitting  into  the 
groove  R.  The  whole  is  then  raised  to  the  press,  the  upper 
part  of  the  lower  die  D  joining,  and  forming  a  continuation  of 
the  core  B,  and  the  ring  C  entering  into  the  groove  S.  The 


FIQ.146 


lower  die  D  is  then  revolved  until  the  lugs  d  d  lock  into  the 
hooks  H  H,  as  shown  in  Fig.  144,  the  whole  forming  a  com- 
plete mould  for  the  socket.  When  the  socket  is  formed  the 
lower  die  D  is  withdrawn,  and  the  ring  C  separated  and  re- 
moved. 

To  facilitate  the  manipulations  of  the  ring  C  the  inventor  at- 
taches to  the  segments  thereof  the  arms  L  L1  (see  Figs.  144 


440 


BRICK,  TILES   AND   TERRA-COTTA. 


and  145),  hinged  upon  the  wrist  F  attached  to  the  bar  P. 
Upon  the  wrist  O,  journaled  in  the  bar  P,  are  fastened  the 
lever  G  and  link  M,  and  opposite  ends  of  the  link  M  are  con- 
nected with  the  arms  L  L'  by  the  links  N  N',  the  whole  so 
arranged  that,  by  revolving  the  lever  G,  the  arms  L  L1  may 
be  caused  to  diverge  or  approach  each  other,  carrying  the 
segments  of  the  ring  C. 

The  simple  dividing  ring  C,  for  the  purpose  of  making 
sockets  on  sections  of  straight  pipe,  is  not  new,  but  the  method 
is  new  of  holding  it  by  means  of  the  grooves  in  the  dies  A  and 
D,  and  manipulating  it  by  means  of  the  arms  L  L'  and  at- 
tachments. 

MACHINE    FOR   CUTTING   SEWER-PIPE   RINGS. 

The  machine  shown  in  Figs.  146  to  152   is  for  cutting  rings 


FIG.  151 


THE   MANUFACTURE   OF    SEWER- PIPE.  441 

from  clay-pipe  while  in  the  green  or  undried  condition  in 
which  they  are  formed ;  and  which  rings  are  designed,  after 
burning,  to  be  employed  in  the  construction  of  drains  and 
sewers.  The  invention  consists  in  a  horizontally  vibrating 
wire-carrying  frame  arranged  to  swing  over  a  suitable  pipe- 
supporting  platform,  and  capable  of  being  moved  vertically 
between  each  vibration  and  supported  in  place  during  each 
motion,  so  that  the  pipe  is  divided  by  vibrating  wire  into  suc- 
cessive rings. 

Figure  146  is  a  side  elevation.  Fig.  147  is  a  vertical  section 
through  the  upper  socket,  showing  the  catches  which  support 
the  racks  and  wire-frame.  Fig.  148  is  a  sectional  view,  show- 
ing the  ratchet  of  the  wire-reel.  Fig.  149  is  an  end  view  of  the 
wire-reel  on  an  enlarged  scale,  showing  its  mode  of  attachment 
to  the  lower  arm  of  the  wire-frame.  Fig.  150  is  a  side  view  of 
the  same.  Fig.  151  is  a  perspective  view.  Fig.  152  is  a  sec- 
tional view  on  the  line  x  x,  Fig.  146. 

A,  Fig.  146,  is  an  upright  post  or  other  suitable  support,  to 
which  the  swinging  wire-carrying  frame  is  attached  by  means 
of  the  lugs  or  sockets  L  G  K  and  the  sliding-bar  B. 

P  is  the  pipe,  resting  on  the  fixed  platform  or  stand  [7,  and 
w  the  wire  strained  on  the  swinging  frame,  by  which  the  pipe 
is  cut. 

R  is  a  counter-weight,  by  which  the  swinging  frame  is  bal- 
anced ;  and  C  C'  are  the  racks,  and  h  j  the  catches  by  which 
the  length  of  the  rings  is  determined. 

In  order  to  provide  for  cutting  rings  of  different  lengths,  two 
or  more  racks  C  C'  are  made  on  the  upper  end  of  the  bar  B. 
The  distance  between  the  teeth  of  these  racks  corresponds  with 
the  desired  length  of  the  rings  to  be  cut  by  the  machine. 

The  frame  may  be  made  of  sufficient  strength  to  sustain  the 
wire  w  without  the  curved  arm  E ;  but  it  is  preferable,  for  the 
sake  of  lightness,  to  employ  it.  Where  it  is  not  used  the  two 
rings  vS  and  S'  should  be  connected  by  an  upright  bar,  so  that 
they  oscillate  together. 

In  order  to  prevent  loss  of  time  consumed  in  replacing  the 


442  BRICK,  TILES    AND   TERRA-COTTA. 

wire  when  it  is  accidentally  broken,  the  inventor  attaches  to  the 
ring  S'  a  reel  c,  Figs.  149  and  150,  about  which  a  supply  of 
wire  is  wound. 

In  the  practical  operation  of  this  improved  pipe-cutter,  one 
or  more  of  the  pipes  which  it  is  desired  to  cut  into  rings  being 
placed  upright  on  the  platform  U,  the  operator  swinging  the 
frame  backward  and  forward  from  the  positions  indicated  by  E1 
w'y  Fig.  152,  to  E"  w",  passes  the  wire  through  the  pipe  and 
severs  it.  At  each  end  of  the  oscillating  motion  of  the  swing- 
ing frame,  it  is  raised  upward,  or  depressed  for  a  distance  cor- 
responding with  one  of  the  teeth  of  the  racks  C  or  O  occupy- 
ing in  succession  the  positions  indicated  by  the  dotted  lines  in 
Fig.  152,  and  cutting  a  ring  from  the  pipe  while  moving  in  each 
direction.  A  number  of  pipes  may  be  cut  into  rings  at  one 
time,  if  placed  on  the  ptatform  U.  After  the  completion  of  the 
cutting  operation  the  rings,  which  remain  on  each  other,  are  re- 
moved, and  the  process  repeated. 

It  is  preferable  to  commence  the  cutting  operation  at  the 
lower  end  of  the  pipe,  moving  the  frame  upward  between  each 
cut,  and  using  the  handle  M  only,  to  disengage  the  dog  //  from 
the  rack  C,  when  it  becomes  necessary  to  depress  the  swinging 
frame. 

A  CONTRIVANCE  FOR  PREVENTING  THE  DISPLACEMENT  OF  DRAIN-PIPES  IN 

THE  KILN. 

The  contrivance  shown  in  Figs.  153  to  157  is  the  invention 
of  Mr.  John  Murtagh,  of  Boston,  Mass.,  and  is  for  holding  or 
binding  the  upper  course  of  pipes  during  the  process  of  burn- 
ing, and  the  application  of  this  arrangement  in  works  of  any 
magnitude  cannot  fail  to  result  in  considerable  savings. 

The  object  is  to  prevent  the  displacement  of  the  pipes  when 
in  the  kiln ;  and  the  invention  consists  in  securing  each  pipe  of 
the  top  tier  in  the  kiln  to  its  neighbors,  by  means  of  binders 
made  of  clay  like  that  of  which  the  pipes  are  made,  and  baked 
or  burned  in  the  usual  manner.  Figs.  153  and  154  are  dia- 
grams, Fig.  153  illustrating  the  new  mode  of  securing  the  top 


THE    MANUFACTURE    OF   SEWER-PIPE. 


443 


tier  of  pipes  in  one  way,  and  Fig.  154  in  another,  both  ways  of 
arranging  the  top  tier  being  in  common  use. 

Figs.   1550,   155^,  and    155^  show    three  forms  of   binders. 


FIG.155c 

Figs.  156  and  157  illustrate  the  relation  of  the  pipes  and 
binders  before  and  after  burning. 

The  binders  a  are  formed  of  the  clay  used  in  making  the 
pipe,  or  of  other  suitable  clay,  with  a  body-piece,  from  which 
project  two  or  more  legs,  as  shown  in  Figs.  155^,  155^  and 
155^,  and  then  burned  in  a  proper  kiln,  with  the  pipes.  When 
thus  made  they  are  hard,  and  although  brittle,  like  other 
crockery  or  pottery  ware,  are  yet  abundantly  strong  for  the 
purpose.  One  set  of  them  can  be  used  from  twenty  to  thirty 
times  before  they  become  too  much  vitrified. 

In  filling  the  kiln  the  unburned  pipes  are  placed  in  the  usual 
way,  but  the  pipes  in  the  upper  tier  are  connected  each  with 


444 


BRICK,  TILES   AND   TERRA-COTTA. 


its  neighbors  by  these  binders,  as  illustrated  in  Figs.  153  and 
154,  where  A  represents  the  pipes,  and  a  the  binders.  This 
makes  the  upper  layer  of  pipes  one  compact  mass,  and  does 
away  with  all  danger  of  their  getting  out  of  place  in  burning, 
thereby  preventing  them  from  becoming  bent  or  adhering  to- 
gether in  masses.  Binders  a'  are  used  to  connect  the  tier  of 
pipes  with  the  wall  of  the  kiln,  special  brick  a*  being  built  into- 
the  wall  to  engage  with  the  end  of  the  binders. 


FIG.  158. 


The  pipes  shrink  in  burning,  so  that  the  binders  should  fit 
loosely  when  the  kiln  is  set,  as  shown  in  Fig.  156.  Fig.  157 
shows  the  position  of  the  pipes  after  they  are  burned. 

The  barrow  shown  in  Fig.  158  is  intended  for  wheeling 
sewer-pipe  and  drain-pipe,  and  it  is  built  very  substantially,  the 
wheel  being  of  iron,  and  the  remainder,  with  the  exception  of 
the  back  braces,  being  of  wood. 


TABLE  SHOWING  DIAMETER  AND  THICKNESS   AND  AVERAGE  WEIGHT  PER  FOOT 
OF  SALT-GLAZED  VITRIFIED  SEWER-PIPE,  USUALLY  KEPT  IN  STOCK 

BY  MANUFACTURERS. 
Diameter  of  pipe.  Thickness  of  pipe. 


IO 
12 

H 

II 

18 

20 
22 
24 


inch 


Weight  of  pipe  per  foot. 
6  pounds. 


16 

21 

32 

42 

50 


II 


no 
160 


THE   MANUFACTURE    OF    SEWER-PIPE. 


445 


Double-strength  pipe  usually  costs  about  30  per  cent,  addi- 
tional to  that  of  ordinary  strength. 

Many  manufacturers  furnish  pipe  and  branches  only  in  two- 
foot  lengths,  and  furnish  additional  lengths  only  to  special 
order. 

CAPACITY  OF  SEWER-PIPES  FOR  RESISTING  PRESSURE. 

The  best  grades  of  salt-glazed  vitrified  sewer-pipes  will  stand 
an  inside  pressure  of  100  to  140  pounds  per  square  inch,  ac- 
cording to  diameter  of  pipe. 

They  will  stand  an  outside  pressure  of  14,000  to  40,000 
pounds  per  square  inch,  before  cracking  or  crushing,  according 
to  diameter  of  pipe. 

To  find  ,the  pressure  in  pounds  per  square  inch  of  a  column 
of  water,  multiply  the  height  of  the  column  in  feet  by  0.434. 
Approximately,  every  foot  elevation  is* is  equal  to  y2  Ib.  pres- 
sure per  square  inch ;  this  allows  for  ordinary  friction. 

A  "  miner's  inch"  of  water  is  the  quantity  discharged 
through  a  hole  one  inch  square,  six  inches  below  the  surface  of 
the  water,  measuring  from  the  top  of  the  opening,  and  is  ap- 
proximately equal  to  12  U.  S.  gallons  per  minute. 

Pressure  per  square  inch  of  columns  of  water:  25  ft.  head, 
10.82  Ibs. ;  50  ft.  head,  21.65  Ibs.;  100  ft.  head,  43.30  Ibs. ;  150 
ft.  head,  64.85  Ibs.;  200  ft.  head,  86.60  Ibs.;  250  ft.  head, 
108.25  Ibs.;  300  ft.  head,  129.90  Ibs. 

Doubling  the  diameter  of  a  pipe  increases  its  capacity  four 
times.  Friction  of  liquids  in  pipes  increases  as  the  square  of 
the  velocity. 

When  salt-glazed  vitrified  pipes  of  clay  are  used  for  water 
conduits,  extra  long  sockets  should  be  formed  upon  the  pipes 
for  the  purpose  of  making  a  strong  joint,  capable  of  resisting 
the  desired  pressure. 

The  drain-pipe  for  sewerage  purposes  now  employed  in  this 
country  and  in  Europe  is  in  various  shapes,  but  the  circular 
form  is  the  one  in  most  general  use. 


CHAPTER  XIII. 


THE  MANUFACTURE  OF  DRAIN  TILE. 

DRAIN  TILE  for  agricultural  underground  drains  are  usually 
circular,  and  measure  from  2^  in.  to  12  in.  in  diameter  and 
one  foot  in  length.  The  following  table  gives  the  prices  as 
F.  O.  B.,  at  factory  say  in  central  Ohio,  no  allowance  being 
made  for  breakage : 

DRAIN  TILE IN  ONE  FOOT  LENGTHS. 


Inside 
Diameter. 

PRICE. 

Branches 
each. 

Weight  per 
foot. 

2Kin. 

3       " 
4 

8 

10 
12 

$12.00  p 
15.00     ' 
22.CO 
30.00 
44.00 
80.00 
120.00 
I50.CO 

ar  i  ooo  feet  

7  c- 
8  c. 

10   C. 
12   C. 

15  c. 

25  c. 
40  c. 
60  c. 

3  Ibs. 
4  Ibs. 
6  Ibs. 
8  Ibs. 
12  Ibs. 
1  8  Ibs.      • 
28  Ibs. 
42  Ibs. 

<       «       « 

«       « 

(( 

« 

« 

« 

« 

Over  12  in.  in  diameter  the  tile  are  usually  24  in.  long. 

They  can  be  made  of  about  the  same  kind  of  sandy  clay  as 
bricks,  and  are  burned  sufficiently  to  include  as  much  porosity 
and  toughness  as  possible. 

There  is  no  reason  why  tiles  of  this  kind  cannot  be  produced 
cheaply  in  almost  any  neighborhood. 

Clay  used  for  the  manufacture  of  building  brick  will  make 
good  drain-tile,  care  being  observed,  however,  not  to  have  the 
clay  too  sandy,  as  tile  made  from  such  clays  would  be  too 
weak  to  stand  distant  shipment.  In  mining  the  clay  from  the 
bank  it  should  be  thoroughly  mixed  from  the  top  to  the  bot- 

(446) 


THE   MANUFACTURE   OF   DRAIN   TILE.  447 

torn  of  the  clay  bank,  and  some  clays  when  thus  mined  and 
mixed  give  good  results  when  the  clay  is  taken  directly  from 
the  bank.  Some  clays  require  to  be  dug  in  the  autumn  or 
winter  and  exposed  to  the  frost,  while  others  may  be  spaded 
up  and  exposed  to  the  action  of  the  air  for  a  longer  or  shorter 
time  with  beneficial  results.  Clays  of  all  characters  used  in  the 
manufacture  of  drain-tiles  will  be  more  or  less  improved  by 
being  run  through  a  pulverizer.  It  is  only  through  practical 
test  that  the  best  clay  can  be  selected  for  the  manufacture  of 
drain-tile,  as  it  is  impossible  to  foretell  the  various  peculiarities 
which  will  be  developed  in  drying  and  burning  various  clays. 
One  rule,  however,  may  be  laid  down,  that  is  that  an  open, 
coarse,  gritty,  sandy,  non-plastic  clay  will  not  make  good 
drain-tile.  The  clay  used  for  this  purpose  should  be  plastic, 
smooth  to  the  touch,  and  possessing  such  characteristics  as 
would  commend  it  for  the  manufacture  of  a  good  grade  of 
building  brick.  Any  clay  selected  for  the  purpose  should 
possess  the  quality  of  drying  in  the  open  air  without  damage. 

PREPARING  AND  HANDLING  CLAY  FOR  TILE.* 

Build  the  factory  near  the  clay — it  is  better  for  the  farmers 
to  haul  the  tile  a  long  distance  than  for  the  maker  of  tile  to 
haul  the  clay.  With  the  factory  located,  and  the  capital  small 
and  the  demand  for  tile  likely  to  be  limited,  purchase  a  horse- 
power tile  mill,  erect  a  round-crowned  kiln  17  feet  in  diameter 
or  a  12x15  ft-  crowned  kiln  10  feet  high,  erect  sheds  and  pur- 
chase trucks.  The  capacity  with  five  men  is  a  kiln  a  week — it 
must  not  be  less.  System  is  necessary  to  success,  hence  sys- 
tematize the  work  as  follows :  Monday,  empty  and  fill  the  kiln 
and  fire  in  the  evening.  Tuesday,  clean  the  sheds  and  make 
tile,  continuing  through  Wednesday  and  Thursday.  Friday, 
haul  clay  with  two  carts,  strip  off  the  top  soil  and  mix  the 
spadings  of  clay  well  in  the  pit.  The  temperer  remains  in  the 
pit,  levels  each  load,  and  adds  to  each  spading  the  necessary 

*  Read  by  Mr.  John  G.  Wagner,  of  Covington,  Ky.,  before  the  Ohio  Tile  and 
Drainage  Association,  February  14,  1888. 


448  BRICK,  TILES    AND   TERRA-COTTA. 

amount  of  water.  The  clay-temperer  should  not  use  a  hose  or 
let  the  water  run  on  the  clay.  The  man  who  tempers  the  clay 
should  have  good  judgment  and  quick  discernment.  The  in- 
terested eye  of  the  owner  must  supply  the  missing  link  here  as 
well  as  elsewhere.  On  Saturday  haul  the  wood  or  coal  and 
make  every  provision  for  an  early  start  on  Monday. 

After  a  few  successful  years,  if  accumulated  capital  and  the 
demand  for  tile  justify  in  enlarging  the  works,  purchase  a 
larger  machine,  put  in  steam-power,  erect  another  kiln  of  the 
size  above  given.  A  kiln  that  can  be  emptied  and  filled  in  a 
day  is  the  best.  More  kilns  rather  than  larger  ones  should  be 
the  rule. 

After  the  works  have  been  enlarged  it  is  preferable  to  em- 
ploy a  different  method  of  getting  in  the  clay.  Construct  an 
iron  (T-rail)  track,  use  side  dumping-cars  and  a  ^  wire  rope. 
With  these  appliances  a  man  and  a  mule  can  haul  clay  sufficient 
to  keep  the  machine  running.  Divide  the  pit  into  two  parts, 
each  part  holding  a  kiln  of  tile,  fill  and  temper  one  side,  and 
while  it  is  being  used  fill  and  temper  the  other.  If  the  clay 
can  be  allowed  to  stand  a  day  or  so  in  the  pit  after  being  tem- 
pered, it  works  better.  The  engineer,  who  is  close  by,  has 
ample  time  to  level  and  sprinkle  the  clay  as  it  is  dumped  in  the 
pit.  Have  near  by  a  forty-barrel  tank  of  water,  filled  with  a 
jet  pump.  This  tank  is  a  valuable  adjunct  to  the  factory.  At- 
tach a  hose  to  the  tank  in  sprinkling  the  clay. 

In  early  spring  the  clay  comes  from  the  bank  sufficiently 
moist.  To  preserve  this  state  of  moisture  cover  the  bank  with 
a  few  loads  of  straw,  which  saves  much  hard  spading  and  ob- 
jectionable clods.  It  is  not  best  to  use  clay  direct  from  the 
bank,  so  pass  it  through  the  tempering  pits.  The  handling 
and  the  action  of  the  air  improve  the  working  of  the  clay. 
With  steam  power  it  is  best  to  use  a  good  crusher. 

No  rules  will  enable  every  tile  or  brickmaker  to  prepare  the 
clay  aright.  He  must  learn  thoroughly  the  nature  of  his  clay 
and  how  to  manipulate  it. 

Most  clays  are  benefited  by  wintering,  but  this  is  expensive ; 


i 


THE   MANUFACTURE   OF   DRAIN   TILE.  449 

yet  with  some  clays  it  is  money  saved  to  spade  them  and  let 
them  weather  through  the  winter. 

Strong  clays  which  crack  badly  are  benefited  by  mixing  with 
them  the  dust  of  crushed  bits  of  brick  and  tile,  or  by  adding 
sand,  or  if  these  are  not  to  be  had,  use  saw-dust  or  coal-dust. 
The  tile  will  be  weaker  where  saw-dust  or  coal-dust  is  used,  but 
strong  enough  probably  for  all  practical  purposes. 

Those  having  much  trouble  with  their  clays  can  learn  useful 
lessons  from  sewer-pipe  and  pottery  manufacturers.  A  visit  to 
Trenton,  N.  J.,  or  East  Liverpool,  or  Akron,  O.,  may  be  a  pro- 
fitable investment  of  time  and  money,  in  seeing  how  the  manu- 
facturers at  those  points  work  their  clays. 

DRAIN  TILE  :    ITS  MANUFACTURE  AND  USE.* 

The  subject  assigned  me  may  be  considered  by  some  as  for- 
eign to  the  line  of  thought  laid  out  by  the  convention  proper, 
but  as  many  of  us  are  acting  in  a  dual  capacity,  tile  makers 
and  brickmakers,  and  to  others  perhaps  who  do  not  fully  know 
the  use  of  drain  tile,  an  idea  might  be  dropped  that  would 
engender  new  thought  which  would  be  beneficial. 

Drain  tile,  which  is  absorbing  at  the  present  time  a  large 
amount  of  labor  and  capital,  especially  in  the  Western  states, 
had  its  origin  most  marked  in  the  first  century  of  the  Christian 
era.  Calumella,  a  Roman  contemporary  with  the  philosopher 
Seneca,  in  the  reign  of  Nero,  treats  at  length  and  with  fullness, 
not  inelegantly,  of  the  cultivation  of  all  kinds  of  grain,  garden 
vegetables,  trees,  the  vine,  olive  and  other  fruits.  He  gives 
directions  for  selecting  farms,  the  management  of  servants  and 
slaves.  He  himself  lived  in  Rome  most  of  the  time,  but  owned 
a  small  villa  and  farm  in  the  country.  He  advanced  the  idea 
of  loosening  the  soil  in  various  ways — by  cultivation,  and  to 
quote  his  words,  he  says,  "  For  to  cultivate  is  no  other  thing 
but  to  loosen  and  ferment  the  earth ;  therefore  the  same  land 
which  is  both  fat  and  loose  and  crumbling  yields  the  greatest 

*From  a  paper  by  E.  M.  Pike,  Esq.,  of  Chenoa,  111.,  read  January  22,  1891,  at  the 
Fifth  Annual  Convention  of  the  National  Brick  Manufacturers'  Association. 
28 


450  BRICK,  TILES   AND   TERRA-COTTA. 

profit,  because  at  the  time  it  yields  the  most  it  requires  the 
least."  He  speaks  of  the  different  kinds  of  soil,  whether  it  be 
woody,  stony  or  marshy  land,  covered  with  rushes,  fern  plants 
or  shrubs. 

He  says  if  it  be  wet  let  the  abundance  of  moisture  be  first 
drained  or  dried  up  by  ditches — of  these  we  have  known  two 
kinds,  blind  and  open.  Then  he  describes  the  manner  in 
which  the  blind  ditches  were  made  with  stone  and  clean  gravel, 
but  if  these  were  not  obtainable  to  make  bundles  of  brush  tied 
together,  on  which  were  laid  boughs,  over  which  the  earth  was 
thrown,  leaving  the  ends  open  for  the  free  passage  of  water 
both  in  and  out.  Thus  we  can  see  that  they  had  some  knowl- 
edge of  the  benefit  of  under-drainage  as  far  back  as  the  begin- 
ning of  the  Christian  era,  and  I  have  helped  make  the  same 
kind  of  a  ditch  in  Maine,  my  native  state,  in  my  boyhood  days, 
and  it  worked  well.  We  have  no  knowledge  that  the  Romans 
used  drain  tile  for  draining  land,  but  the  same  author  speaks 
of  the  use  of  earthen  pipe  to  convey  water  to  cisterns  as  fol- 
lows :  "  But  if  these  also  fail  you,  and  the  small  hopes  of  spring 
water  force  you,  let  large  cisterns  be  built  for  men,  and  ponds 
for  cattle,  for  gathering  and  keeping  rain  water,  which  is  most 
proper  and  suitable  for  the  health  of  the  body,  and  this  you 
may  have  exceedingly  good  if  you  convey  it  in  earthen  pipes 
into  a  covered  cistern." 

I  infer  from  the  foregoing  that  earthen  pipes  were  on  the 
market,  and  doubtless  cheap,  for  we  have  no  information  that 
would  lead  us  to  believe  that  the  tariff  was  heavy  on  these 
pipes,  or  that  strikes  were  frequent.  So  far  as  we  know  this  is 
the  oldest  reference  to  under-drains  for  agricultural  purposes. 
There  is  plenty  of  evidence  that  stone,  which  was  common  to 
the  country,  and  brick  also,  were  used  in  construction  of  sewers 
in  cities  centuries  before  the  time  of  Columella,  and  perhaps 
earthen  pipes  may  have  been  used  for  the  same  purpose ;  but 
we  have  knowledge  of  the  making  of  brick  with  and  without 
straw  as  far  back  as  the  tower  of  Babel,  over  4,000  years  ago, 
and  this,  allow  me  to  suggest,  was  the  first  strike  that  ever 
occurred  on  a  building  or  a  brick  yard. 


THE   MANUFACTURE    OF   DRAIN   TILE.  451 

Drain  tile  at  the  present  time  are  usually  made  round,  one 
foot  in  length  and  of  all  sizes  from  three  to  eighteen  inches  in- 
clusive. 

In  the  past,  not  many  years  ago,  they  were  made  horse-shoe 
shaped,  with  and  without  bottoms,  also  V-shaped  with  the  open 
side  down,  and  perhaps  other  shapes,  but  at  present  the  round 
tile  for  convenience  of  manufacture  and  use  supersedes  all 
other  shapes.  They  are  manufactured  by  machinery  made  in 
this  country,  which  is  unsurpassed ;  moulded  and  dried  on 
slatted  floors  or  shelves  and  usually  burned  in  close  kilns,  after 
which  they  are  ready  for  use. 

The  benefit  derived  from  drain  tile  scarcely  any  one  disputes, 
for  we  have  learned  that  they  are  not  only  beneficial  to  drain  the 
water  away,  but  also  beneficial  in  time  of  drought.  The  bene- 
fits arising  from  tile  drainage  are  many.  It  lengthens  the 
seasons  at  both  ends.  It  enables  the  seed  to  go  into  the 
ground  earlier  in  the  spring,  makes  it  grow  faster  during  the 
summer,  and  matures  the  crop  earlier  in  autumn.  Franklin 
said,  "Burn  a  candle  at  both  ends  and  it  is  soon  gone."  A 
season  that  is  ushered  in  amid  the  cold  wet  days  of  May  and 
closed  by  early  frosts  of  September  is  too  short  for  success- 
ful farming.  The  draining  obviates  this  by  draining  and  warm- 
ing the  soil ;  it  being  more  mellow  and  open  to  the  circulation 
of  the  air,  will  thaw  out  earlier  in  the  spring. 

We  who  have  lived  in  snowy  countries  have  observed  that 
the  culverts  under  the  roadways  and  the  banks  of  ravines  and  the 
hill-sides  were  the  first  to  get  bare  in  the  spring,  and  thus 
drainage  warms  the  soil.  Actual  experience  has  shown  us  that 
drained  soil  is  about  ten  degrees  warmer  eight  inches  below 
the  surface  than  undrained  soil  at  the  same  depth.  Heat  is 
necessary  to  the  germination  of  seeds  and  growth  of  plants, 
whether  the  tiny  flower  of  the  hot-house  or  the  expansive  fields 
of  corn  on  the  western  prairie,  and  the  seed  that  will  thrive  in 
warm  underdrain  soil  will  rot  in  cold  damp  soil,  so  that  often- 
times the  few  degrees  of  heat  betters  the  condition  of  the  seed 
into  life  and  growth,  and  plant  life  is  hastened  by  the  same 


45 2  BRICK,  TILES    AND   TERRA-COTTA. 

helping  causes,  and  consequently  larger  crops,  earlier  matured, 
of  better  quality  result  than  on  cold  undrained  soil.  We  can  also 
see  that  the  same  order  of  things  would  bring  the  harvest 
earlier,  and  therefore  less  liable  to  the  early  frosts  of  autumn. 

We  have  said  that  drainage  is  beneficial  in  dry  weather. 
The  rainfall  percolates  through  the  earth  to  the  tile,  some  three 
feet  below  the  surface,  creating  innumerable  pores.  In  dry 
weather  these  same  pores,  opened  by  action  of  the  water,  be- 
come breathing  holes,  all  centering  on  the  tile.  These  open- 
ings create  a  draft  through  the  tile,  which  brings  the  night  air 
laden  with  moisture  that  comes  in  contact  with  the  soil,  which 
is  cooler,  and  the  dampness  is  thus  taken  up.  The  earth 
virtually  breathes — exhales  water  in  wet  seasons  and  inhales 
moisture-laden  air  in  dry  seasons,  thus  showing  tile  drainage  to 
be  a  safeguard  against  drouth  as  well  as  over-abundance  of 
water. 

"  White  man  brings  rain,"  says  the  Indian.  He  brings  it  by 
cultivating  the  soil  and  covering  it  with  verdure ;  but  this  same 
white  man  has  become  wise  enough  to  drain  away  what  he 
does  not  want. 

A  few  years  ago  quite  a  commotion  was  raised,  and  on  first 
thought  too  that  the  tile  makers  were  ruining  this  country  by 
draining  the  water  away  and  destroying  evaporation,  and  this 
theory  was  substantiated  by  professors  in  agricultural  colleges 
and  others,  also  that  tile  draininge  was  conducive  to  floods ; 
but  after  due  investigation,  just  the  reverse  are  the  facts.  Tile 
drainage  throws  the  water  level  lower,  stores  it  for  a  time  in 
the  earth,  prevents  surface  wash  and  too  much  rapid  evapora- 
tion ;  the  earth  becomes  spongy  and  loose  and  easily  cultivated. 

If  we  look  back  over  the  history  of  this  country  we  shall  find 
far  longer  drouths  many  years  previous  to  the  laying  of  any  tile. 

It  might  be  of  interest  to  those  present  to  know  to  what  an 
extent  this  enterprise  has  been  carried  on  in  the  western  states. 
Illinois,  for  instance,  has  about  800  factories,  and  from  best 
statistics  obtainable,  have  made  and  laid  about  200,000  miles, 
or  enough,  if  laid  continuously,  to  belt  the  earth  eight  times ; 


THE    MANUFACTURE   OF   DRAIN   TILE.  453 

this  reduced  to  rods  makes  64,000,000 ;  calculating  the  laying 
of  this  tile  at  thirty  cents,  and  the  cost  of  them  twenty-five 
cents  per  rod,  which  is  a  fair  average  in  Illinois,  would  make 
the  sum  of  $35,200,000.  There  are  larger  estimates  than  this. 
To  those  not  knowing  the  value  of  drain  tile  this  might  seem  an 
extravagant  expenditure  of  money,  but  allow  me  to  say  that  no 
money  is  so  well  expended  as  that  judiciously  expended  in  tile. 

Illinois  is  not  alone  in  this  great  enterprise.  Indiana  and 
Ohio  are  close  behind,  while  Iowa,  Kansas,  Missouri  and 
Michigan  are  fast  falling  into  line,  and  our  friends  of  the  South 
have  been  watching  us  in  this  enterprise,  and  they  too  have 
gone  into  the  business. 

There  are  other  benefits  outside  of  agriculture.  Take  all 
this  vast  amount  of  drainage  in  a  sanitary  point  of  view,  we 
can  imagine,  and  imagine  only,  its  benefits. 

In  earlier  years  fever  and  ague,  o?  the  shakes  in  common 
parlance,  were  as  common  as  sunny  days  ;  but  tile  drainage  has 
carried  away  the  shakes  by  draining  out  the  miasmatic  ponds. 
The  frogs  and  the  mosquitoes  too  have  gone,  but  the  shakes 
have  left  their  foot-prints  on  the  brows  of  many  hairless-headed 
men,  of  which  you  have  a  specimen  before  you. 

The  advantages  of  the  use  of  tile  are  manifest  on  every  hand, 
with  these  millions  of  capital  invested  and  thousands  of  men 
employed.  It  has  stimulated  mining  and  transportation,  and 
given  new  impetus  to  local  trade  in  hundreds  of  towns  and 
villages  in  states  where  factories  are  established,  also  business 
to  manufacturers  of  machinery,  and  labor  to  mechanics  of  other 
states.  From  the  standpoint  of  to-day  the  future  looks  bright 
to  the  farmers,  and  so  it  does  to  all,  whether  they  work  with 
brain  or  brawn. 

Clay  is  a  theme  as  broad  as  the  world  and  deep  as  the  earth, 
universal  in  all  climes  and  countries.  Clays  are  of  many  kinds, 
composed  of  many  elements,  and  we,  as  clay  manipulators, 
analyze  them  practically  rather  than  theoretically,  for  by  prac- 
tice only  can  we  know  how  to  handle  our  own  clay.  If  we 
tried  theory  rather  than  practice,  it  would  be  like  book-farming, 
it  would  run  to  theory  and  the  corn  would  run  to  weeds. 


454  BRICK,  TILES   AND   TERRA-COTTA. 

This  great  system  of  farm  drainage  which  is  taking  the 
country  both  north  and  south,  is  creating  capital  by  the  millions, 
which  will  be  spent  largely  in  building  and  beautifying  homes 
for  the  people  ;  and  we,  as  brickmakers,  are  already  called  upon 
to  tear  down  and  build  greater  manufactories  in  order  to  supply 
the  present  and  coming  demands.  Our  country  is  becoming 
more  favorable  to  human  existence,  wet  lands,  bogs  and  mias- 
matic swamps  are  giving  place  to  dry  and  arable  fields,  and  the 
influence  is  felt  by  countless  thousands  who  breathe  pure  air 
and  enjoy  the  sanitary  benefits  as  a  consequence,  and  yet  this 
work  is  only  begun.  Emerson  says,  "Tiles  are  political  econo- 
mists, so  many  young  Americans  announcing  a  better  era  and 
a  day  of  fat  things."  Older  Americans  are  also  announcing  a 
better  era,  and  the  more  tiles  they  use  the  more  fat  things  they 
will  have. 

These  annual  associations  are  conducive  of  much  good.  We 
meet  for  our  mutual  benefit  and  to  advance  our  mutual  interests. 
Our  vocation  is  a  noble  one ;  we  add  wealth  and  happiness  not 
only  to  the  present,  but  to  generations  yet  unborn.  The  pro- 
ducts of  our  toil  in  shape  of  burned  clay  will  stand  after  we 
have  passed  into  the  great  beyond.  We  build  better  than  we 
know. 

Every  clay  worker  knows  the  lamentable  lack  of  available 
knowledge  pertaining  to  the  clay  business.  In  our  business 
every  one  has  had  to  work  out  his  own  problem  and  to  over- 
come his  own  difficulty  by  his  own  experience.  All  know  the 
cost  of  this  in  time,  money  and  mental  anxiety.  The  policy  a 
hundred  years  ago  of  potters  was  to  keep  secret  all  they  knew 
and  not  let  others  profit  by  their  experience.  At  the  Royal 
potteries  in  England  neither  king  nor  subject  could  enter  those 
secret  workshops,  the  workmen  themselves  being  sworn  to 
secrecy.  But  in  our  day  of  "reciprocity"  and  reciprocal 
knowledge,  we  are  above  that ;  we  have  discovered  that  indi- 
vidual progress  in  our  calling  is  very  much  due  to  interchange 
of  individual  experience. 

Life  is  too  short  for  each  one  of  us  to  learn  by  long  and  hard 


THE   MANUFACTURE   OF   DRAIN   TILE.  455 

experience  that  which  can  be  told  us  by  another  who  has  gone 
through  it.  We  clay  workers  have  enough  to  do  to  uncover 
the  unseen,  which  is  constantly  rising  before  us  in  the  shape  of 
costly  experience,  and  should  aid  each  other  in  cutting  corners 
to  success,  and  then  gain  time  for  fitting  foundations  for  the 
palaces  of  brick  yet  to  be  built  by  the  craft,  either  with  or 
without  straw,  whether  hard,  soft  or  salmon,  glazed  or  re- 
pressed. Strikes  and  walking  delegates  will  only  be  known  in 
history. 

ELEVATING   DEVICES    FOR    BRICK   AND   TILE. 

Fig.  159  illustrates  an  endless  elevator,  with  swinging  shelves, 
in  position  to  carry  drain-tile  to  two  upper  floors. 

Platform  elevators  are  also  used  to  do  the  same  work.  The 
platform  is  generally  made  8x4  feet,  so  that  a  man  and  loaded 
truck  can  be  lifted  at  once.  Both  of^ these  forms  of  elevators 
are  furnished  by  the  Frey-Sheckler  Co. 

DRYING   DRAIN-TILE. 

Different  clays  require  different  methods  of  drying,  for,  while 
some  tile-clays  are  so  tough  as  not  to  dry  properly  in  the  sun, 
others  are  so  tender  that  it  is  difficult  to  dry  them  in  the  air. 
It  is  the  lack  of  uniformity  and  the  employment  of  too  high  a 
temperature  at  first  in  drying,  and  not  the  after  rapidity  with 
which  the  tile  are  dried,  which  usually  causes  the  tile  to  crack. 
The  drying  of  the  surface  too  rapidly  will  crack  the  green  tile, 
for  the  reason  that  the  centre  of  the  tile  is  raw,  and  does  not 
shrink  as  rapidly  as  the  surface. 

Many  manufacturers  of  tile  could  not  succeed  very  well  with- 
out steam-drying,  especially  in  the  early  and  latter  part  of  the 
season.  One  tile-maker,  whom  I  now  recall,  used  6800  feet  of 
one -inch  steam  pipe  in  a  shed  30  by  120  feet,  two  stories  in 
height,  and  he  made  and  marketed  18  kilns  of  tile  one  season 
before  the  other  factories  in  his  neighborhood  began  opera- 
tions. 

The  Wolff,  and  similar  forms  of  dryers,  will  dry  ordinary  tile 
in  24  hours  without  cracking  the  ware. 


456 


BRICK,  TILES   AND   TERRA-COTTA. 


When   the  tile   are   green  the  temperature   in  the  dryer,  or 
shed,  should  not  exceed  70°  F.     When  the  tile  are  dry  enough 

FIG.  159. 


THE   MANUFACTURE   OF   DRAIN   TILE. 


457 


to  turn,  increase  the  temperature  as  the  tile  will  stand  it,  so 
that  when  the  tile  are  about  dry  the  thermometer  will  indicate 
150°  F. 

DRYING  IN  OPEN  SHEDS. 

Drain-tile  are  usually  dried  in  sheds  more  or  less  open  in 
their  construction,  having  doors  so  arranged  at  the  sides  of  the 
shed  as  to  allow  the  admission  of  air  into  the  drying  apart- 
ments in  such  quantity  as  may  be  needed,  and  as  the  nature  of 
the  clay  may  require. 

BURNING  DRAIN-TILE. 

In  the  burning  of  drain-tile,  as  in  the  burning  of  sewer-pipe, 
it  is  essential  that  the  tile  should  be  thoroughly  dry ;  the  drier 
the  tile  the  better  the  success  to  be  attained.  The  time,  fuel, 
and  other  items  of  cost,  which  have  to  be  expended  for  the 
thorough  drying  of  the  tile  in  the  kSn,  might  just  as  well  be 
saved,  if  possible,  by  utilizing  the  natural  method  of  drying. 
The  manner  of  setting  the  tile  in  the  kiln  is  also  an  imporant 
item,  and  the  method  employed  varies  with  the  various  kilns  in 
use.  When  the  Dutch  or  open-top  kiln  is  employed,  it  is  usual 
to  set  the  small  tile  in  the  bottom  of  the  kiln ;  the  larger  tile  is 
then  placed  in  the  central  tier,  the  smallest  tile  being  placed  in 
the  upper  portion  of  the  kiln,  and  in  no  case  should  the  tile  be 
allowed  to  come  in  contact  with  the  walls ;  a  space  of  about 
one  inch  and  a  half  should  be  left  open  all  around  the  side  of 
the  kiln.  When  the  up-draft  or  crown-top  kilns  are  employed 
for  burning  drain-tiles,  the  method  of  setting  is  similar  to  that 
which  has  just  been  described,  although  it  is  found  from  ex- 
perience that  better  results  are  obtained  if  the  tile  of  the  largest 
diameter  are  set  near  the  top.  When  the  down-draft  kiln  is 
used  for  burning  the  drain-tile,  it  is  desirable  that  the  large  tile 
should  be  set  at  the  top,  care  being  observed,  however,  not  to 
place  the  larger  tile  at  the  points  of  extreme  heat.  And  in 
kilns  of  this  character  it  is  desirable  that,  if  there  are  any  tiles 
which  are  not  thoroughly  dry,  they  should  be  set  at  the  bottom 
of  the  kiln,  so  as  to  obviate  the  necessity  of  driving  the  water- 
smoke  from  the  damp  tile  through  those  which  are  dry. 


458  BRICK,  TILES   AND   TERRA-COTTA. 

The  method  of  nesting  the  tile  varies  with  different  clays ; 
some  clays  will  allow  close  nesting,  while  other  clays  require  to 
to  be  nested  very  openly.  No  rule  for  nesting  the  tile  can  be 
laid  down ;  the  best  method  to  be  employed  can  be  developed 
only  from  thorough  knowledge  of  the  practical  qualities  of  the 
clay  to  be  burned.  In  order  to  avoid  the  cracking  and  loss 
from  improper  nesting,  it  is  desirable  that,  where  defects  of  this 
character  occur,  the  cause  should  be  thoroughly  investigated 
and  a  memorandum  made  of  the  result  upon  the  books  at  the 
works.  If  some  such  simple  system  as  this  could  be  adopted 
in  the  various  clay-works  of  the  country,  and  the  result  of  the 
practical  experiences  could  be  brought  out  at  the  conventions, 
or  recorded  in  the  pages  of  the  journals  devoted  to  the  clay 
industry,  great  good  would  result  to  the  trade  in  many  of  its 
branches. 

In  firing  the  tile  care  should  be  observed  not  to  push  the 
burning  too  rapidly ;  only  a  light  fire  should  at  first  be  used  in 
the  fire-box ;  then  the  heat  should  be  raised  very  gradually, 
fuel  being  added  in  smallest  quantities,  as  nothing  is  to  be 
gained  from  pushing  the  burning  of  the  tile  in  its  early  stages. 
The  water-smoke  must  be  driven  off  gradually,  but  surely,  until 
at  last  none  of  it  can  be  discerned  mixed  with  the  blue-black 
smoke  which  issues  from  the  top  of  the  flues  or  stack. 
Patience  worketh  wonders  in  burning  drain-tile,  as  in  burning 
all  other  classes  of  clay  products.  Of  course  the  drier  the  tile 
the  quicker  the  kiln  may  be  burned  off;  but,  as  it  is  not  possi- 
ble to  have  all  of  the  tile  of  a  uniform  degree  of  dryness,  all 
the  dry  tile  have  to  be  held  back  until  the  moisture  has  been 
thoroughly  driven  from  the  damp  tiles,  otherwise  crushing, 
cracking,  and  other  losses  will  result.  Even  after  the  water- 
smoke  has  been  thoroughly  driven  off,  it  is  desirable  not  to  push 
the  burning  too  rapidly ;  gradually  increase  the  heat  until  the 
tile  have  been  brought  to  nearly  the  melting-point,  and  at  this 
temperature  the  heat  should  be  maintained  for  two  or  three 
hours ;  great  caution,  however,  should  be  observed  not  to  in- 
crease the  heat  to  the  actual  fluxing  point,  for  in  such  a  case 


THE   MANUFACTURE    OF   DRAIN   TILE. 


459 


the  tile  would  run  together  and  the  kiln  prove  a  loss.  With 
some  clays,  however,  it  will  be  necessary  to  maintain  the  final 
heat  all  the  way  from  four  to  eight  hours.  The  kiln,  when 
burned  off,  should  remain  closed  for  about  twenty  to  twenty- 
four  hours,  after  which  time  it  may  be  gradually  opened  and 
allowed  to  cool. 

The  proper  management  of  open-top  kilns,  especially  in 
burning  drain-tile,  is  discussed  in  a  practical  manner  in  the 
January  (1889)  number  of  the  Drainage  Journal  as  follows: 

"  While  it  is  true  that  open-top  kilns  are  not  generally  in 
good  favor  among  our  leading  tile  manufacturers,  it  is  also  true 
that  there  are  quite  a  number  of  them  in  use.  They  are  not 
the  best  kilns,  but  they  serve  a  good  purpose  oftentimes,  where 
the  burner  knows  how  to  burn  in  them.  Indeed,  we  know  some 
who  burn  excellent  tile  in  open-top  kilns.  The  suggestions 
that  we  make  have  a  practical  side  m  our  judgment  that  will 
apply  to  other  kilns  in  some  respects.  They  are  briefly  as 
follows :  Set  the  tile  a  little  open  in  the  corners  and  at  points 
where  the  difficulty  of  getting  a  draft  of  heat  is  experienced. 
Make  the  openings  over  the  heat  flues  larger  at  such  points  so 
as  to  allow  the  heat  a  freer  passage,  and  closer  at  the  points 
where  it  has  been  inclined  to  draw  heretofore.  In  bringing  the 
kiln  to  a  red  heat  after  the  water-smoke  is  off,  keep  the  spots 
that  have  been  inclined  not  to  burn  well  in  advance  of  other 
portions  of  the  kiln.  It  is  pretty  well  known  to  burners  that 
the  hot  places  tend  to  get  hotter.  It  will  be  well  to  keep  the 
side  arches  where  the  tile  have  not  burned  well  heretofore,  in 
advance  in  the  heating  to  water-smoke.  The  general  firing  of 
the  kiln  after  the  red-heat  point  has  been  reached  should  look 
sharply  to  the  points  suggested.  Where  there  is  a  tendency  in 
one  portion  of  the  kiln  to  fall  behind,  the  burner  may  increase 
the  heat  in  the  better  fuel  used,  or  by  using  a  fuel  that  will  send 
a  flame  up  through  the  ware,  and  thus  increase  the  draft  of 
heat  at  the  point  desired.  After  a  high  heat  has  been  reached 
in  the  kiln,  except  at  such  points  as  are  inclined  to  lag,  it  is 
the  practice  of  some,  in  the  use  of  open-top  kilns,  to  open  the 


460  BRICK,  TILES   AND   TERRA-COTTA. 

platting  in  the  centre  of  the  cooler  spots,  and  set  three  or  four 
large  tile  on  top  of  each  other,  setting  them  in  the  opening  in 
the  platting.  The  tile  serves  as  a  flue  to  increase  the  draft  and 
draw  the  heat  through  the  cold  spots.  Others  cover  the  hot 
spots  of  the  kiln  tight,  and  in  this  way  drive  the  heat  where  it 
is  wanted,  which  may  be  done  by  covering  with  sheet-iron,  and 
afterwards  throwing  three  or  four  inches  of  dirt  on  the  iron. 
By  tight  planting  in  the  way  suggested,  the  heat  can  be  taken 
to  the  sides,  or  to  the  centre,  or  to  the  centre  and  sides,  as  may 
be  desired. 

"  Again,  we  call  attention  to  the  heat-flues.  They  may  not 
be  large  enough  or  open  enough  on  top,  or  too  open ;  also  the 
setting  of  the  ware  of  any  kind  will  have  much  to  do  with  the 
result  in  burning.  The  burner  should  be  a  man  of  good  prac- 
tical common  sense,  quick  to  observe  what  is  going  on,  and  al- 
ways ready  to  apply  the  necessary  means  '  to  get  there,'  as  the 
boys  say.  "Talent  may  know  why  this  and  that  should  be 
done,  but  it  is  'tact'  that  knows  how,  seizes  the  opportunity 
and  does  it.  The  'tact'  men  are  in  demand  for  burners. 
They  make  all  kinds  of  kilns  go." 

BURNING  DRAIN-TILE  WITH  NATURAL  GAS. 

The  burning  of  drain-tile  with  natural  gas  is  about  the  same 
as  the  process  of  burning  with  wood  or  coal,  the  main  differ- 
ence being  in  the  proper  regulation  of  the  draft,  and  the  draft 
required  to  obtain  the  best  results  can  only  be  learned  by  trial. 
A  round  down-draft  kiln,  20  feet  in  diameter,  set  1 3  high  in 
the  centre,  is  the  style  of  kiln  which  we  shall  select  for  describ- 
ing the  process.  If  connected  by  a  two-inch  main  with  the 
natural  gas  well  at  a  distance  of  from  one  to  two  miles,  the  pipe 
will  supply  enough  gas  to  burn  two  kilns,  run  the  engine,  and 
heat  the  dry  shed  and  dwelling,  with  40  pounds  pressure. 

If  the  kiln  is  not  given  draft  enough,  the  tile  will  not  be 
burned  sufficiently ;  if  only  a  little  more  draft  be  given  than  is 
usual  with  wood  or  coal  fuel,  the  fire  boxes  are  liable  to  be 
melted  down,  and  the  top  tile  will  be  too  hard  and  out  of  shape, 


THE   MANUFACTURE    OF   DRAIN   TILE. 


461 


while  the  bottom  tile  will  be  too  soft.  By  increasing  the  draft, 
and  holding  the  heat  longer  than  with  either  coal  or  wood, 
good  results  will  be  obtained.  The  tile  can  be  dried  in  less 
time  than  with  wood  or  coal ;  but  with  natural  gas  the  firing 
should  continue  about  twelve  hours  longer.  With  wood  the 
kilns  could  be  finished  in  twelve  hours  after  the  red  heat  is 
uniform  through  the  kiln ;  but  with  natural  gas,  hold  it  24  to 
30  hours. 

While  driving  off  the  water-smoke  it  is  necessary  to  give  the 
kiln  but  little  attention.  Fire  the  kiln  in  the  evening,  turning 
on  what  gas  the  tile  will  stand,  and  do  not  visit  it  any  more 
until  next  morning,  when  turn  on  more  gas,  and  at  noon  in- 
crease the  fires,  so  that  by  night  the  water-smoke  is  mostly  off; 
then  the  fires  should  be  increased  so  that  by  midnight  the  fire- 
boxes, if  the  clay  will  allow,  should  be  as  hot  as  they  will 
admit  of  being  without  dropping  the*arches.  From  this  time 
on,  visit  the  kiln  every  hour  or  so  to  see  that  none  of  the  fire- 
boxes get  too  high  a  heat.  When  the  heat  is  well  through  the 
kiln,  begin  to  slacken  the  fires,  so  that  the  top  tile  may  not  get 
too  much  heat  before  the  bottom  gets  enough. 

TILE-MAKING    MACHINES. 

Fig.  1 60  shows  the  Improved  Centennial  Machine,  made  by 
the  Frey-Sheckler  Co.  One  of  many  valuable  features  of  this 
machine  is  its  great  pugging  capacity.  It  is  provided  with 
two  shafts,  which  revolve  in  opposite  directions,  one  running 
at  a  speed  five  times  faster  than  the  other. 

It  is  adapted  for  the  production  of  Drain  Tile,  Fire  Proofing, 
Terra-Cotta,  Lumber,  Building  and  Fire  Brick. 

This  cut  shows  the  Improved  Centennial  in  connection  with 
the  Combination  Table  arranged  for  making  Drain  Tile  and 
Hollow  Blocks. 

This  machine  will  make  drain  tile  as  large  as  20  inch 
diameter. 

The  cut  also  shows  a  variety  of  work  made  on  this  machine. 

The  Combination  Table,  which  is  shown  in  connection  with 


462 


BRICK,  TILES   AND   TERRA-COTTA. 


THE    MANUFACTURE   OF   DRAIN   TILE. 


463 


the  Improved  Centennial  Machine,  is  especially  adapted  for 
cutting  Tile,  Hollow  Building  Blocks,  Fire  Proofing,  Terra- 
Cotta  Lumber,  etc.  The  cutting  wires  can  be  easily  shifted,  so 
as  to  cut  the  various  lengths  required.  Suitable  straight  rollers 
are  furnished  for  brick  and  hollow  blocks,  while  those  of  tile 
have  depressions  in  them  for  one,  two  or  three  streams  of  tile. 

All  sizes  of  tile,  up  to  and  including  5  inches  in  diameter, 
are  cut  and  handled  on  the  rollers;  from  6  inches  to  10  inches 
in  diameter  are  cut  and  handled  in  copper-lined  or  wooden 
troughs,  that  are  made  to  fit  the  table. 

A  suitable  bed  for  the  use  of  the  Osman  Patent  Tile  Carrier 
is  also  furnished  with  this  Table,  when  desired,  for  tile  larger 
than  7  inches  in  diameter.  For  large  hollow  blocks  an  addi- 
tional cutting  frame  of  suitable  size  can  be  attached  in  place  of 
the  small  one.  A  screw  adjustment  raises  and  lowers  the  Table 
to  any  desired  height. 

The  Machine  and  Table  will  occupy  16  feet  by  4  feet  6  inches 
floor  space.  Weight  of  Machine  and  Table  4,225  pounds. 
Any  of  The  Frey-Sheckler  Cutting  Tables  can  be  used  in  con- 
nection with  the  Improved  Centennial  Machine. 

Fig.  161  represents  the  Brose  Patent  Tile  Table  for  cutting 
and  handling  Tile  from  10  inches  to  20  inches  diameter, 
usually  24  inches  long,  made  by  the  Frey-Sheckler  Co.  The 
mode  of  operating  is  as  follows :  After  the  large  trough  and 
guide,  as  shown  by  the  cut,  are  thoroughly  oiled  the  machine 
is  started,  when  the  tile  runs  through  the  guide  into  the  trough, 
then  the  Table  is  released,  so  that  it  partakes  of  the  motion  of 
the  tile,  thereby  securing  a  straight  cut  by  means  of  the  wires 
on  the  cutting  frame.  When  cut,  the  table  is  tilted  on  the 
gudgeons,  requiring  very  little  effort,  and  the  tile  is  thereby  up- 
ended on  a  board  which  has  been  previously  placed  on  the 
roller-frame  on  the  end  of  the  trough.  This  brings  the  end  of 
the  tile  on  the  board  near  to  the  floor,  where  a  two-wheeled 
truck,  with  two  long  prongs  (which  reach  under  the  board),  is 
used  to  carry  the  tile  away  to  its  place.  As  the  large  tile, 
when  two  feet  long  and  twenty-five  inches  on  the  outside, 


464 


BRICK,  TILES    AND   TERRA-COTTA. 


weigh  nearly  two  hundred  pounds,  it  will  be  seen  that  this 
mode  and  arrangement  is  needed  to  handle  them.  By  a  lever, 
the  table  is  drawn  back  and  held  against  the  machine  until 


FIG.  161. 


BROSE'S  PATENT  TILE  TABLE. 

ready  to  cut,  the  trough  being  held  by  a  spring  catch,  which  is 
released  by  the  foot  of  the  operator  when  the  trough  is  tilted. 
Weight  of  Table,  160  pounds. 

Fig.  162  represents  the  Leach  Patent  Table,  also  made  by 
the  Frey-Sheckler  Co.  This  Table  is  intended  for  tile  above 
four  inches  and  as  large  as  twelve  inches  in  diameter.  The 
troughs  are  self-adjusting,  fitting  the  different  sizes  of  round 
tile  named.  It  will  be  noticed  that  all  the  receiving  troughs, 
which  are  made  of  sheet  metal,  are  hung  together  as  a  con- 
tinuous chain  so  that  the  pipe  as  it  emerges  does  not  have 
to  slide  across  the  metal,  but  makes  the  trough  follow  along, 


THE   MANUFACTURE   OF   DRAIN   TILE. 
FIG.  162. 


465 


LEACH  PATENT  TILE  TABLE. 

fitting  the  next  one  to  it  in  position  for  the  tile.  This  Table 
works  very  nicely  and  will  also  dump  the  tile  on  a  board  if 
held  in  position  at  the  end  of  the  table.  Weight,  170  pounds. 

DODD'S    CARRIER    FOR   HORIZONTAL   TILE   MACHINE. 

The  Dodd  Carrier  is  shown  in  Figs.  163  to  165,  and  by  its 
use  tile  of  different  diameters  may  be  carried  by  the  same  set 
of  supporting  bars,  instead  of  being  compelled  to  change  the 
bars  for  others  having  a  concavity  formed  to  suit  the  periphery 
of  every  different  size  of  tile  manufactured.  This  result  is  ac- 
complished by  forming  the  concavity  in  the  carrier-bar  upon 
as  great  a  radius  as  the  largest  tile  to  be  made  upon  the 
machine,  and  bridging  the  space  between  the  ends  of  the  bar 
with  a  strap  of  flexible  material,  upon  which  the  tile  is  received. 

Fig.  163  is  a  perspective  view  of  a  carrier  complete,  having 

its  carrier-bars  provided  with   flexible   straps.     Fig.  164   is  a 

cross-section  of  a  carrier  showing  the  position  assumed  by  the 

flexible  strap  when  carrying  a  tile.     Fig.  165  is  a  perspective 

30 


466 


BRICK,  TILES   AND   TERRA-COTTA. 


view  of  one  of  the  bars  and  straps,  with  a  section  of  the  carrier- 
belt. 

In  constructing  this  machine  the  carrier-frame  A  is  formed 
in  the  usual  manner  of  two  side  pieces  connected  by  cross-bars 
a,  and  supported  upon  short  legs  b',  or  by  any  other  suitable 
means.  Above  the  cross-bars  a,  which  connect  the  two  sides 
of  the  frame,  is  placed  a  series  of  rollers  c,  which  support  the 
endless  carrier-belt  or  belts  B.  To  this  belt  are  secured  by 

FIG.  163. 


FIG.  165. 

screws  or  other  proper  means  the  carrier-bars  C.  These  bars 
have  a  cavity  or  hollow  in  the  side  opposite  that  which  is 
attached  to  the  carrier-belt,  and  bridging  this  cavity  is  the  flex- 
ible strap  D,  secured  at  each  end  to  the  carrier-bars  C  by 
means  of  screws  e  or  other  proper  fastening  devices.  These 
straps  D  may  be  formed  of  leather,  rubber  belting,  canvas,  or 
any  other  material  possessing  sufficient  strength  and  flexibility, 


THE   MANUFACTURE   OF   DRAIN   TILE. 


467 


it  being  necessary  that  they  should  give  a  firm  support  to  the 
tile,  and  at  the  same  time  conform  readily  to  its  shape.  In  at- 
taching the  straps  D  to  the  carrier-bars  it  is  preferable  to  allow 
the  strap  to  drop  or  sag  a  little,  as  is  clearly  shown  in  Fig.  165 
of  the  drawings,  as  it  is  thereby  caused  to  conform  more  readily 
to  the  shape  of  the  tile. 

Tne  frame  provided  with  carrier-belt  and  carrier-bars  having 
a  concave  receiving  surface  to  receive  the  tile  as  it  comes  from 
the  forming-dies  is  old,  but  the  combination  of  the  carrier-bars 
and  a  flexible  bridging  strap  arranged  to  receive  the  tile  as  it 
issues  from  the  forming-die  is  a  new  idea. 


CHAPTER  XIV. 

THE  MANUFACTURE  OF  ARCHITECTURAL  TERRA-COTTA. 

TERRA-COTTA  is  to-day  the  most  available  material  used  for 
the  construction  of  buildings  of  all  classes  and  forms.  It  is,  in 
fact,  the  concrete  part  of  them.  It  is,  as  well,  indispensable 
in  every  assemblage  of  artistic  architectural  ornamentation  and 
has  virtually  taken  the  place  of  stone,  and  is  now  used  in  the 
completion  of  seven-tenths  of  the  structures  erected.  The  use 
of  terra-cotta  dates  prior  to  the  time  to  which  our  histories 
reach  —  in  fact,  it  is  said,  "  that  the  children  of  Seth,  the  son  of 
Adam,  built  two  pillars;  one  of  brick  and  one  of  stone,  and  they 
inscribed  upon  each  of  them  the  discoveries  they  made  con- 
cerning the  heavenly  bodies,  so  that  their  i 


preserved  to  mankind  and  not  be  lost  before  they  became  suf- 
ficiently known."  .  Brick  was  the  building  material  of  the  ante- 
diluvian days.  The  word  terra-cotta  was  then  unknown,  but 
after  all  it  is  but  a  refined  baked  clay,  and  some  large  stones 
must  have  been  used  in  order  to  have  models  or  inscriptions 
placed  on  them.  In  1765  an  old  well  was  opened,  accidentally,  by 
some  workmen  at  the  Porta  Latina,  at  Rome.  In  it  were  found 
Egyptian  and  Roman  statues  in  terra-cotta,  which  were  taken 
to  England.  Bas-reliefs  were  also  exhumed  at  the  same  time. 
Among  the  features  of  Roman  ceramic  art  are  its  metopes  and 
historic  friezes.  The  exquisite  bas-reliefs  of  Luca  della  Robbia 
are  known  to  all  lovers  of  the  beautiful. 

Terra-cotta,  a  name  in  itself  Italian,  was  first  applied  by  Ital- 
ians more  to  the  purposes  of  ornamentation  than  of  construc- 
tion. The  clay  was  plastic  and  easily  treated. 

Terra-cotta  has  great  lasting  qualities  when  made  of  the 
proper  mixture  of  clays  and  when  well  fired.  It  will  not  vege- 

(468) 


MANUFACTURE   OF   ARCHITECTURAL   TERRA-COTTA.      469 

tate  as  stone  will,  often  causing  decay.  It  is  interesting  to 
examine  a  piece  of  this  material  in  cold  weather  under  a  mag- 
nifying glass.  It  will  be  found  to  contain  almost  infinitesimal 
icicles,  but  the  strength  of  the  composition  is  so  great  that  it 
will  withstand  the  natural  expansion  without  injury.  In  beauty 
of  color  it  has  an  advantage  over  stone,  for  by  the  use  of  chemi- 
cals almost  any  color  can  be  produced,  and  they  are  found  to 
be  less  apt  to  change  under  atmospheric  influences.  In  terra- 
cotta we  can  find  a  scope  for  freedom,  with  a  capability  of  sup- 
plying the  increasing  demand  for  decoration  in  the  most  dur- 
able material.  The  beauty  of  all  things  decorative  should  grow, 
and  as  terra-cotta  is  comparatively  cheap,  it  has  become  an 
ornamental  factor. 

It  is  an  interesting  sight  to  stand  in  a  studio  of  a  modern 
terra-cotta  factory  and  witness  the  work  of  the  artists  in  this 
material,  who  with  intelligence  stand  before  large  easels  sup- 
porting masses  of  clay,  carving  bas-reliefs  from  sketches.  Many 
of  them  seem  to  love  their  work.  One  often  finds  a  small  boy 
at  his  easel  moulding  some  simple  device.  A  model  having 
been  perfectly  prepared,  a  piece  mold  is  then  taken  of  it  in  such 
manner  as  to  allow  of  its  being  easily  withdrawn  without  injury 
to  the  model.  Much  skill  is  required  in  making  the  plaster 
molds  to  fit  the  model ;  great  practical  knowledge  and  experi- 
ence are  required.  Bungling  in  this  is  sure  to  prove  fatal  to 
the  work,  and  men  of  superior  ability  are  usually  assigned  the 
task.  The  clay  is  not  forced  in  en  masse,  but  deftly  pressed 
against  the  sides  of  the  mold.  It  is  really  impressive  to  see 
the  transformation  of  this  plastic  material  into  a  substance 
which  is  more  imperishable  than  granite. 

The  modelers  should  possess  great  dignity  of  thought  and 
imagination,  and  it  has  been  suggested  that  the  work  should 
be  given  the  artist's  personal  attention — in  fact,  that  the  mold- 
ing of  the  model  should  be  executed  by  his  own  hands,  that  it 
may  not  lose  his  individual  conception  of  the  subject  and  that 
in  not  doing  the  work  the  standard  of  artistic  excellence  is 
being  rapidly  lowered. 


470  BRICK,  TILES   AND   TERRA-COTTA. 

Terra-cotta  is  now  used  in  every  feature  of  decoration ;  it 
forms  the  facing  of  walls  in  interiors ;  it  paves  floors.  Bas- 
reliefs,  piers,  capitals,  arches,  shafts,  corbels,  chancels  and 
arcades  are  composed  of  it. 

Terra-cotta,  the  most  enduring  of  all  building  materials,  has 
been  used  to  a  greater  or  less  extent  from  a  high  antiquity  in 
continental  Europe,  and  in  England  terra-cotta  trimmings  were 
used  in  building  as  early  as  the  fifteenth  century.  In  the  United 
States  this  material  does  not  seem  to  have  been  introduced 
until  after  1850.  Experiments  were  made  in  this  direction  in 
J^53  by  Mr.  James  Renwick,  a  prominent  New  York  architect, 
&  but  the  innovation  was  not  received  with  favor  by  builders.  In 
1870  the  Chicago  Terra-Cotta  Company  brought  over  from 
England  Mr.  James  Taylor,  superintendent  of  the  well-known 
works  which  were  established  by  Mr.  J.  M.  Blashfield,  in  1858. 
By  the  introduction  of  the  English  methods,  the  Chicago  estab- 
lishment soon  turned  out  better  work  than  had  been  before 
produced  in  the  United  States. 

The  Perth  Amboy  Terra-Cotta  Company  was  incorporated 
in  1879,  and  at  once  embarked  in  the  manufacture  of  large  de- 
signs for  architectural  purposes  from  clay  obtained  from  the 
neighboring  deposits.  The  plant  of  this  company  has  expanded 
so  rapidly  that  at  present  it  includes  twenty-two  kilns,  some  of 
them  measuring  forty-eight  and  one-third  feet  in  height  and 
twenty-four  and  one-sixth  in  diameter,  (see  frontispiece)  which 
are  said  to  be  the  largest  of  the  kind  on  this  continent,  if  not 
in  the  world. 

The  company  has  in  its  employ  a  number  of  eminent  artists 
in  this  particular  line,  and  has  furnished  terra-cotta  details  for 
many  prominent  buildings  throughout  the  country.  Of  these 
we  may  mention  Young  Maennerchor  Hall,  Philadelphia ;  Ponce 
de  Leon  Hotel,  St.  Angustine,  Florida ;  Biological  Laboratory, 
Princeton  College ;  and  Central  School,  Ironton,  Ohio. 

Since  about  1880  the  demand  for  architectural  terra-cotta 
has  rapidly  increased,  and  to-day  many  manufactories  are  in 
operation  in  various  parts  of  the  country.  In  the  latter  part  of 


MANUFACTURE   OF   ARCHITECTURAL  TERRA-COTTA       471 

1885  the  New  York  Architectural  Terra-Cotta  Company  was 
organized,  and  the  services  of  Mr.  James  Taylor  secured  as 
superintendent.  The  works  at  Long  Island  City  have  furnished 
designs  for  more  than  two  thousand  buildings,  scattered 
throughout  the  principal  cities  of  the  Union.  They  have  lately 
succeeded  in  producing  a  pure  white  terra-cotta,  which  is  said 
to  be  fully  equal  to  the  red  in  durability  and  hardness,  and 
they  have  used  this  latest  invention,  in  combination  with  buff 
brick,  in  the  rebuilding  of  Harrigan's  Theatre,  New  York.  The 
effect  is  novel  and  pleasing.  Other  architectural  terra-cotta 
works  have  also  been  recently  experimenting  in  the  same  di- 
rection, and  it  is  now  only  a  question  of  a  short  time  when  the 
more  perishable  marble,  as  a  building  material,  will  be  super- 
seded by  this  more  enduring  substitute.  Having  eliminated 
the  red  coloring  matter  from  the  composition,  it  would  seem 
possible,  by  the  introduction  of  other  tints,  to  produce  terra- 
cotta in  yellow,  blue,  or  any  shade  desired.  The  possibilities 
in  this  direction  appear  almost  limitless. 

The  Indianapolis  Terra-Cotta  Company,  located  at  Bright- 
wood,  Ind.,  commenced  business  under  its  present  management 
in  1886.  Mr.  Joseph  Joiner,  a  gentleman  of  large  experience 
in  this  field,  and  a  highly  qualified  architect,  superintends  the 
manufacturing  department. 

In  the  same  year,  Messrs.  Stephens  &  Leach  started  a  factory 
for  architectural  terra-cotta  in  West  Philadelphia,  Penn.  and  later 
the  firm  name  was  changed  to  Stephens,  Armstrong  &  Conkling, 
and  later  to  Stephens  &  Co.,  which  concern  is  now  run  as  a 
branch  of  New  York  Architectural  Terra-Cotta  Co.  During 
the  nine  years  of  the  works'  existence  it  has  furnished  material 
ior  hundreds  of  important  structures  in  Philadelphia  and  other 
cities,  of  which  particular  mention  may  be  made  of  panels  and 
gable  work  in  the  library  of  the  University  of  Pennsylvania, 
and  the  Drexel  Institute,  erected  in  West  Philadelphia.  A 
series  of  animal-head  medallions,  in  high  relief,  are  particularly 
excellent,  and  some  bas-relief  portraits  of  eminent  men,  mod- 
eled by  such  sculptors  as  H.  J.  Ellicott,  John  Boyle,  and  E.  N. 


472 


BRICK,  TILES   AND   TERRA-COTTA. 


Conkling,  are  among  their  best  productions.  Specimens  of  the 
work  of  this  company  are  shown  in  Figs.  166  to  172,  and  of 
the  New  York  Architectural  Terra  Cotta  Co.,  in  Figs.  173  to 
181.  Admirable  work  is  also  being  produced  by  other  estab- 
lishments in  Boston,  Chicago,  and  most  of  our  larger  cities. 


FIG.  1 66. 


FIG.  167. 


MANUFACTURE    OF   ARCHITECTURAL   TERRA-COTTA.      473 
FIG.  1 68. 


FIG.  169. 


474 


BRICK,  TILES   AND   TERRA-COTTA. 
FIG.  170. 


FIG.  171, 


FIG.  172. 


MANUFACTURE   OF   ARCHITECTURAL  TERRA-COTTA.      475 

FIG.  173. 


FIG.  174. 


476 


BRICK,  TILES   AND   TERRA-COTTA. 

FIG.  175. 


FIG.  176. 


FIG.  177. 


FIG.  178. 


MANUFACTURE   OF  ARCHITECTURAL  TERRA-COTTA.      4/7 


478 


BRICK,  TILES   AND   TERRA-COTTA. 


I* ,<0<17 


-5 


The  evidences  of  the  material  prosperity  of  this  country  are 
probably  more  fully  displayed  in  its  street  architecture  than  in 
any  other  manner.  With  the  marvelous  increase  in  real  estate 
values  during  the  past  twenty  years,  there  has  been  a  coincident 


MANUFACTURE   OF   ARCHITECTURAL   TERRA-COTTA.      4/9 

growth  in  the  size  and  decoration  of  its  buildings.  The  con- 
centration of  commercial  and  social  interests  has  created  a  de- 
mand for  vast  structures ;  the  accretion  of  wealth  has  given  the 
means  to  erect  them ;  the  immense  advance  in  the  ability  of 
iron  workers  has  furnished  the  skeleton,  while  the  clay  workers 
have  provided  a  large  part  of  the  material  necessary  to  com- 
plete the  form.  I*  say  a  large  part,  for  the  student  of  architec- 
tural design  in  this  country  will  not  only  find  that  there  are 
very  few  noticeable  buildings  anywhere  which  have  been 
erected  more  than  twenty  years,  but  also  that  a  very  large  pro- 
portion of  the  structures  which  attract  his  attention  are  de- 
pendent upon  terra- cotta  work  for  their  enrichment. 

Now  an  examination  of  the  designs  of  these  buildings  will,  I 
believe,  divide  them  into  two  classes. 

First. — Designs  in  which  terra-cotta  has  been  used  as  a 
stitute  for  stone. 

Second. — Designs  in  which  terra-cotta  has  by  its  facility  of 
formation  furnished  the  architect  with  a  freedom  of  expression 
that  enabled  him  to  give  scope  to  his  fancy  and  produce  re- 
sults impossible  to  the  school  of  line,  square  and  plummet. 
The  further  fact  will  also  become  apparent,  viz :  that  much  of 
the  recent  great  advance  in  freedom  of  design  in  this  country 
began  with  the  advent  of  the  architectural  terra-cotta  worker. 

When  the  use  of  burned  clay  in  other  forms  than  common 
brick  was  suggested  to  our  architects,  they  at  once  gravitated 
towards  two  distinct  ideas : 

1.  Terra-cotta  as  a  substitute. 

2.  Terra-cotta  as  a  distinct  "building  material." 

Some  architects  were  attracted  by  the  hope  of  having  found 
a  cheap  substitute  for  stone,  which  would  enable  them  to  get 
more  show  for  less  cost.  Such  architects  would  ask  for  large 
pieces,  rock  surfaces  and  stone  colors.  They  would  select  a 
chip  of  natural  stone,  and  demand  that  the  clay-worker  do  an 
impossibility,  viz. :  reproduce  that  exact  shade  of  color,  ignor- 

*  From  an  article  by  Mr.  James  Taylor. 


480  BRICK,  TILES   AND   TERRA-COTTA. 

ing  the  fact  that  the  color  of  the  stone  is  in-.i  great  measure 
due  to  the  texture  of  its  surface. 

Stone  work  always  presents  a  section  of  the  material  and 
shows  the  grain,  while  terra-cotta  always  presents  an  outer  skin 
produced  by  the  concentration  of  the  finer  particles  of  the  clay 
at  the  surface  of  the  mould  in  pressing  the  material  into  the  de- 
sired shape.  In  stone  the  carved  work  differs  in  color  from  the 
plain  surface.  Yet  the  material  is  identical. 

As  to  uniformity  of  color  in  terra-cotta,  it  can  only  be  ob- 
tained in  one  way,  and  that  is  available — let  the  painter  have  a 
chance. 

The  pursuit  of  cheapness  never  yet  had  any  artistic  value ; 
therefore  it  is  useless  to  expend  thought  on  the  question  of 
terra-cotta  as  a  substitute  or  sham  building  material.  Terra- 
cotta is  a  valuable  material ;  it  has  a  practical  utility  and  is 
capable  of  artistic  expression  in  architecture.  It  is  the  materi- 
alized crayon  sketch. 

The  proper  use  of  terra-cotta  demands : 

1.  Moderate  size  of  pieces. 

2.  Manipulation  of  the  surfaces. 

3.  Consideration  in  the  construction.* 

4.  Protection  of  the  exposed  joints. 

5.  Freedom  of  shade  in  color. 

It  must  always  be  remembered  when  making  designs  for 
•execution  in  terra-cotta  that  the  material  is  plastic  during  all 
the  processes  of  manufacture.  It  has  to  be  pressed  into  plaster 
moulds  to  give  it  the  desired  form,  then  it  has  to  be  dried  be- 
fore it  can  go  into  the  kiln,  during  which  processes  it  will  con- 
tract and  lose  about  one-twenty-fourth  of  its  bulk  and  one- 
twentieth  of  its  weight.  This  shrinkage  continues  during  the 
process  of  burning,  and  makes  the  total  contraction  about  one- 
twelfth  and  the  reduction  of  weight  about  one-fourth.  If  the 
size  and  form  are  moderate,  this  shrinkage  will  be  obtained 

*  What  I  wish  to  insist  upon  is  the  necessity  of  taking  into  consideration  the  ma- 
terial used  in  construction.  Thus :  Iron  can  be  used  as  beam  lintels,  stone  may 
sometimes  be  so  used  too,  but  terra-cotta  should  never  be  so  used.  James  Taylor. 


MANUFACTURE    OF   ARCHITECTURAL  TERRA-COTTA.      481 

without  cracking  or  distortion  and  with  but  small  risk  of  failure. 
The  same  conditions  affect  the  surfaces  of  the  material ;  unequal 
drying  causes  varied  contraction,  which  the  high  light  of  sun- 
shine apparently  magnifies ;  therefore  terra-cotta  should  never 
have  a  smooth  surface  for  exterior  work.  Many  treatments  of 
surface  are  in  vogue,  such  as  tooled,  combed,  stippled  and 
crinkled  finish  ;  all  of  these  are  used  to  convey  the  idea  of  a  soft 
and  plastic  material. 

The  use  of  terra-cotta  sometimes  leads  to  great  errors  in 
construction.  It  is  customary  to  speak  of  terra-cotta  as  being 
light  in  weight ;  but  this  is  only  true  in  regard  to  transportation 
of  the  surfaces,  for  when  terra-cotta  is  set  in  place  and  properly 
filled  (so  as  to  preclude  the  formation  of  pockets  of  water, 
which  means  ice  in  winter),  it  becomes  the  same  actual 
weight  as  brickwork  and  very  much  of  the  same  construction, 
therefore  all  excessive  projections,  spans  or  openings  ought  to 
receive  a  good  and  sufficient  backbone  of  iron  construction. 

There  are  instances  in  New  York  City  where  cornices  with 
three  feet  of  projection  are  simply  covered  with  inverted  boxes 
of  terra-cotta,  each  box  capable  of  containing  many  gallons  of 
water,  and  at  about  every  two  feet  there  is  a  convenient  joint, 
which,  when  the  pointing  becomes  a  little  loosened  (as  it  will), 
will  freely  admit  the  rain  water  and  let  it  soak  into  the  walls,  so 
that  in  the  winter  time  ice  will  be  formed  in  these  boxes  and 
breakage  may  result.  Surely  this  is  not  the  fault  of  the  terra- 
cotta, though  the  material  is  often  blamed  in  such  cases.  In  a 
a  climate  of  such  extremes  as  ours,  it  is  evident  that  all  upper 
surfaces  which  are  traversed  by  joints  ought  to  be  covered  by 
some  sufficient  protection. 

Almost  all  of  the  finest  buildings  in  our  cities  are  disfigured 
by  grimy  and  black  streaks  leading  down  from  the  vertical 
joints  in  the  stone  cornices  or  projecting  mouldings.  This 
could  and  should  be  prevented  by  the  use  of  metal  or  other 
flashings  for  large  projections,  and  raised  joints  for  the  smaller 
ones.  In  the  use  of  terra-cotta  this  is  imperative ;  for  careless 
workmen  will  often  neglect  to  fill  in  the  work  properly  when  it 


482  BRICK,  TILES    AND   TERRA-COTTA. 

is  being  placed  in  its  permanent  position.  Water  and  ice  will 
then  in  due  course  cause  trouble. 

The  color  of  terra-cotta  is  a  frequent  cause  of  contention. 
It  ought  not  to  be.  Absolute  uniformity  of  color  is  beyond 
the  possibility  of  manufacture.  It  should  be  remembered  that 
the  tone  of  color  is  governed  by  the  chemical  constituents  of 
the  clay,  and  the  shade  of  color  is  governed  by  the  degree  of 
heat  involved  in  burning — a  few  degrees  more  causing  the 
darker  shades,  or  a  few  degrees  less  producing  the  lighter 
shades.  The  regulation  of  the  heat  of  a  kiln  of  burned  clay 
(during  the  process  of  firing)  within  certain  limits  is  at  present 
beyond  the  ability  of  the  most  experienced  of  our  clay  workers. 
Hence  it  is  unfair  to  ask  it  of  them.  If  the  question  of  shade 
of  color  is  important  to  a  certain  design,  as  we  have  said,  why 
not  utilize  the  painter?  He  has  a  recognized  field  in  the 
decoration  of  wood  and  iron.  Is  there  any  sound  reason  why 
he  should  not  also  decorate  the  terra-cotta  work?  Mechani- 
cally there  is  none,  for  a  coat  of  lead  paint  will  last  much 
longer  upon  terra-cotta  than  upon  any  other  building  material 
ever  used,  not  excepting  wood  or  iron. 

A  study  of  the  relations  of  terra-cotta  to  architectural  design, 
founded  upon  a  practical  knowledge  of  this  material,  will 
surely  enable  our  architects  to  produce  an  ideal  brick  and 
terra-cotta  structure,  which  shall  as  truly  make  its  mark  in  our 
day  as  did  the  Certosa  of  Pavia,  the  Church  of  St.  Rustico  at 
Caravaggio,  the  Cathedral  of  Cremona,  and  other  buildings  of 
Northern  Italy,  centuries  ago. 

A   TERRA-COTTA    FACTORY. 

The  departments  or  divisions  of  the  work  in  a  terra  cotta 
factory  seem  to  indicate  a  five-storied  building  as  the  most 
convenient  for  the  purpose,  the  divisions  being  as  follows : 

The  basement  or  first  story  for  the  milling  and  storage  of  the 
prepared  clays  and  for  the  operations  which  belong  to  the  firing 
of  the  kilns. 

The  ground  floor  or  second  story  for  the  loading  and  unload- 


MANUFACTURE   OF   ARCHITECTURAL   TERRA-COTTA.      483 

ing  of  the  kilns,  and  for  the  selection  and  fitting  of  the  burned 
product  previously  to  its  delivery  to  the  store  or  purchaser. 

The  third  story  for  the  pressing  and  finishing  and  drying  of 
the  heavier,  coarser,  and  most  bulky  pieces  of  terra-cotta  work. 

The  fourth  story  for  the  pressing,  finishing  and  drying  of  the 
smaller  ornamental  and  finest  description  of  work. 

The  fifth  story  being  reserved  for  the  studios  of  the  modelers 
and  for  the  model  and  mould-making  shops. 

The  model  and  mould-making  shop  is  the  most  important 
portion  of  a  terre-cotta  factory,  and  like  the  head  of  a  man, 
should  be  at  the  top,  so  as  to  be  as  far  as  conveniently  removed 
from  the  dirt  and  noise  of  the  other  departments. 

In  this  department  are  prepared  the  models  and  sculptures 
of  the  business,  and  the  moulds  from  which  the  clay  duplicates 
are  to  be  made. 

The  idea  of  the  architect  having  been  conveyed  to  the  top 
story,  there  takes  a  substantial  form  for  the  first  time,  and  be- 
comes a  material  having  size  and  weight. 

It  then  passes  downward,  and  as  in  all  orderly  progress  does 
not  retrace  its  path ;  if  it  is  of  a  decorative  or  artistic  quality, 
demanding  skilled  labor  rather  than  mere  material,  it  stops 
awhile  on  the  next  story  to  be  put  into  its  proper  progression. 

Panels  with  modeled  surfaces,  sculptured  forms,  finials,  man- 
tels, and  any  other  delicate  works,  are  thus  done  next  to  the 
top,  just  as  all  the  higher  employments  of  men,  such  as  sculp- 
ture, painting,  writing,  calculating,  etc.,  are  performed  with  the 
hands  in  close  proximity  to  the  head.  Should  the  work,  how- 
ever, be  of  a  heavy,  coarse,  or  bulky  nature,  such  requires 
more  muscular  force,  less  mental  service,  and  a  greater  amount 
of  material ;  it  goes  a  story  lower  to  pass  into  its  next  stage  of 
progress. 

In  the  production  of  one  ton  of  terra-cotta  ware  there  are  re- 
quired to  be  used  nearly  700  pounds  of  water,  or  more  than  80 
gallons.  About  70  gallons  of  this  surplus  moisture  will  have 
to  be  evaporated  in  the  process  of  drying,  and  the  final  IO 
gallons  will  pass  off  after  the  work  is  placed  in  the  kiln  in  a 
form  known  as  water-smoke. 


484 


BRICK,  TILES   AND   TERRA-COTTA. 


By  making  the  factory  structure  several  stories  in  height  and 
placing  the  kilns  at  one  end  of  the  same  building  without  any 
intervening  partitions,  it  will  be  found  that  by  the  evaporation 
of  the  moisture  the  drying  of  the  work  can  be  carried  on  in  a 
very  economical  manner. 

FIG.  182. 


BUILDING   FOR  TERRA-COTTA    FACTORY. 


Fig.  182  will  be  found  useful  for  illustrating  the  practical 
workings  of  this  method ;  the  sketch  represents  a  building  five 
stories  in  height,  with  the  kilns  located  at  the  northern  or  cold 
end  of  the  building. 

It  will  be  noticed  that  the  kilns  are  placed  at  one  end  of  the 
shops  and  grouped  together,  so  as  to  concentrate  their  heating 
capacity  in  one  place  as  much  as  possible.  This  is  done  in 
order  to  create  a  constant  stream  of  air  flowing  toward  them 
from  all  parts  of  the  workshops,  attracted  by  the  well-known 
law  which  causes  the  heavy  or  cold  air  to  rush  toward  the 
warmer  or  lighter  air  adjacent ;  and  these  generators  of  draught 
should  always  be  placed  at  the  northern  or  coldest  end  of  the 
building. 

The  floors  and  the  roof  are  not  allowed  to  come  in  contact 
with  either  the  brick  or  iron-work  of  the  kilns,  but  there  is  a 
clear  space  averaging  eight  inches  all  around  them,  which  forms 
a  passage  for  the  moistened  air  to  escape  upward  and  outward, 
as  is  indicated  by  the  arrows  and  dotted  lines  in  the  illustration. 


/ 


MANUFACTURE    OF   ARCHITECTURAL   TERRA-COTTA.      485 

This  area  or  space  is  covered  with  an  umbrella-shaped  hood 
about  eight  inches  above  the  roof-line,  which  prevents  the  rain 
or  snow  from  driving  into  the  building. 

The  iron  smoke-stack  which  passes  through  the  top  story 
should  also  be  so  constructed  as  to  assist  the  ventilation  in  the 
same  direction. 

This  smoke-stack  should  consist  of  a  cylinder  of  light  boiler 
iron,  and  be  made  smoke-tight  to  carry  off  the  smoke  and  surplus 
gases  created  by  the  combustion  of  the  fuel  used  in  firing  the 
kilns. 

This  cylinder  is  inclosed  within  another  cylinder  made  of  the 
same  kind  of  iron,  but  of  sufficiently  large  diameter  to  allow  of 
a  space  of  four  inches  between  the  two  cylinders  for  the  pur- 
pose of  providing  an  air-flue. 

The  outer  cylinder  or  jacket  is  pierced  with  holes  one  inch 
in  diameter  placed  six  inches  apart  diagonally. 

When  the  inner  or  smoke-stack  becomes  heated  by  the  fire 
below  it  creates  a  vacuum  in  the  air-flue,  and  at  once  the  air  of 
the  workshop  rushes  in  as  indicated  by  the  arrows,  and  thus 
passes  up  and  out  under  the  umbrella. 

This  jacketed  and  ventilated  smoke-stack  will  also  form  a 
perfect  protection  from  fires  that  might  be  caused  by  an  over- 
heated flue,  because  it  is  impossible  to  overheat  the  pierced 
jacket;  for  the  hotter  the  smoke-stack  becomes  the  greater  the 
rush  of  air  into  the  air-flue,  and  consequently  the  greater  the 
ingoing  draft  of  cold  moist  air. 

The  elevator-shaft  in  the  centre  of  the  building  and  the  stair- 
ways at  either  end  are  open,  that  is  they  have  no  partitions 
except  those  high  enough  to  prevent  persons  falling  through 
or  walking  off. 

By  these  arrangements  all  the  air  as  it  becomes  heated  rises 
toward  the  kilns  and  escapes  from  the  building  at  the  roof, 
taking  with  it  a  large  portion  of  the  surplus  moisture. 

Another  important  feature  of  this  system  of  ventilation  is  the 
method  of  making  the  window-sashes.  These  should  be  numer- 
ous, and  made  to  slide  up  and  down  as  is  usual  in  house-sashes, 


486  BRICK,  TILES   AND   TERRA-COTTA. 

with  this  exception  :  only  the  upper  sash  ought  to  have  pulleys 
and  weights  to  allow  of  it  being  lowered  at  will ;  the  lower  sash 
ought  to  be  a  fixture,  and  the  sash-frame  should  reach  as  near 
to  the  ceiling  as  possible,  so  as  to  allow  the  highest  strata  of 
air  to  pass  out  easily  when  the  windows  are  open. 

The  advantages  of  such  sashes  are  readily  seen.  First,  the 
workman  can  only  open  the  right  sash — the  top  one.  Second, 
there  is  no  draft  upon  the  work  or  upon  the  workmen,  and  yet 
there  is  an  abundance  of  fresh  air  constantly  passing  through 
the  entire  work-rooms.  The  inlet  of  air  will  always  take  care  of 
itself,  provided  the  builder  will  furnish  the  outlet  and  some 
motive  force  to  accelerate  the  motion ;  this  is  done  in  the 
above-described  method  by  the  radiated  heat  of  the  mass  of 
brick-work  and  the  iron  chimneys  of  the  kilns,  which  heat,  if 
not  so  used,  would  probably  be  wasted. 

Experience  teaches  that  no  matter  how  perfect  the  ventila- 
tion, it  will  not  suffice  to* dry  out  the  surplus  moisture  quickly 
enough  for  profitable  working  without  the  aid  of  some  method 
of  auxiliary  heating. 

TREATMENT    OF    CLAYS. 

The  peculiarities  of  the  clays  necessary  for  the  manufacture 
of  architectural  terra-cotta  have  been  enlarged  upon  in  Chap- 
ter II. 

Having  found  the  clays  which  he  considers  suited  to  his  pur- 
pose, the  maker  next  proceeds  to  further  reduce  the  natural 
shrinkage  by  mechanical  means,  in  order  to  place  the  contrac- 
tion as  far  as  possible  under  his  own  control ;  upon  his  skill  in 
this  detail  will  very  largely  depend  his  success  in  the  produc- 
tion of  sound,  straight,  and  well-formed  terra-cotta. 

There  are  various  methods  of  doing  this,  such  as  by  the 
admixture  of  ashes,  refractory  sands,  crushed  and  ground 
shales,  or  of  crushed  and  ground  burned  clay,  with  the  crude 
or  natural  clay.  The  best  results  are  obtained  by  the  use  of  a 
proportion  of  the  same  clay  burned  and  ground  to  powder, 
technically  known  as  grit  (some  persons  call  it  cement,  but  it 


MANUFACTURE   OF   ARCHITECTURAL  TERRA-COTTA.      487 

is  hard  to  tell  why  they  do  so,  because  its  use  is  the  exact  oppo- 
site of  cementing).  Having  burned  and  ground  to  powder  a 
portion  of  the  crude  clay,  the  next  step  is  to  prepare  a  mixture 
of  such  proper  relative  proportions  as  to  make  a  homogeneous 
and  workable  body,  or  stiff  mud.  The  exact  proportions  will 
always  depend  upon  the  quality  of  the  clay  and  the  knowledge 
of  the  workmen. 

A  safe  and  reliable  rule  will  be  found  in  aiming  to  make  a 
mixture  which,  under  sufficient  burning,  will  contract  only  one- 
sixteenth  in  bulk.  An  easy  method  of  finding  the  proportion 
suited  to  the  crude  clay  is  to  measure  out  three  separate  parcels 
of  mixture  as  follows  :  — 

A.  2  parts  crude  clay,  I  part  grit. 

B.  3  parts  crude  clay,  I  part  grit. 

C.  4  parts  crude  clay,  I  part  grit. 

Mix  each  parcel  separately,  adding  water  enough  to  make  a 
mud  capable  of  being  pressed  into  a  mould.  It  is  important  to 
knead  thoroughly,  and  have  all  three  samples  of  the  same  de- 
gree of  stiffness,  then  press  into  a  mould,  making  each  kind  so 
as  to  know  them  after  they  are  burned ;  dry  slowly  at  the  same 
time,  and  in  the  same  temperature,  and  burn  in  the  same  part 
of  the  kiln. 

If  these  trials  are  made  carefully,  they  will  indicate  clearly 
what  is  the  correct  proportion  of  clay  and  grit  to  be  used  in 
order  to  produce  good  terra-cotta. 

In  judging  of  these  trials  it  will  be  important  to  notice  first 
the  form,  second  the  hardness,  third  the  shrinkage,  fourth  the 
color. 

The  form  determines  the  marketable  quality,  the  hardness 
indicates  the  durability  of  the  form,  the  shrinkage  demonstrates 
its  working  limits,  while  the  color  is  capable  of  adjustment  and 
is  therefore  of  least  consequence. 

When  the  exact  proportions  of  admixture  known  as  body, 
which  will  reproduce  good  forms,  in  a  semi-vitreous  material  of 
approximately  correct  size  and  of  a  reliable  color,  has  been  as- 
certained, the  next  step  to  consider  is  how  to  prepare  it  in  the 
most  economical  manner. 


488  BRICK,  TILES   AND   TERRA-COTTA. 

There  can  be  no  question  of  the  value  of  the  slipping  or 
washing  of  all  clays  for  terra-cotta  work.  This  is  the  method 
adopted  by  Ernest  March  at  Charlottenburg,  and  where  the 
area  of  the  works  and  the  available  capital  will  permit,  it  should 
always  be  done,  indeed  it  must  be  done  for  high  class  work. 

For  ordinary  work  many  of  the  advantges  of  the  washing 
process  can  be  obtained  by  the  use  of  a  cylinder-crusher  and 
stone-separator  for  plastic  clays,  and  the  use  of  a  pulverizer  for 
clays  that  are  of  a  shaly  quality,  such  as  Indiana  clays,  ob- 
tained from  the  block  coal  regions,  and  many  other  clays  that 
are  mined  in  the  neighborhood  of  coal-fields.  The  kind  of 
machinery  to  be  used  must  be  determined  by  every  manufac- 
turer for  himself.  The  nature  of  his  clay  will  indicate  what 
work  he  ought  to  do  in  order  to  properly  prepare  and  temper 
it.  Every  machine  has  some  especially  good  feature,  while  no 
one  is  absolutely  perfect,  or  suited  to  every  description  of  clay 
or  work.  Therefore,  in  selecting  machines,  it  is  well  to  get 
only  those  which  can  readily  be  understood  and  operated  by 
the  purchaser.  Clay-working  is  like  farming,  as  shown  in  the 
maxim  "The  man  is  of  more  consequence  than  the  land,"  so  in 
our  case  the  man  is  of  more  consequence  than  the  machine. 

When  the  clay-reducing  plant  has  been  selected,  the  next 
step  in  order  is  to  prepare  the  grit.  For  cheap  and  coarse 
work,  sharp  and  semi-vitreous  sands  will  be  sufficient,  but  for 
making  a  uniform  grade  of  body,  of  good  color  and  density, 
there  is  no  better  material  for  grit  than  some  of  the  crude  clay 
burned,  crushed,  and  ground  to  a  powder  so  as  to  readily  pass 
through  a  i6-mesh  sieve. 

This  can  be  readily  and  cheaply  obtained  by  putting  lumps 
of  clay  in  all  available  vacancies  among  the  goods  in  the  kiln. 
The  burning  thus  costs  nothing,  because  the  lumps  hold  the 
heat  better  than  air-spaces,  and  the  saving  of  fuel  will  fully 
repay  the  labor  of  putting  in  and  taking  out. 

Having  the  crude  clay  and  ground  grit  in  condition,  we  are 
now  ready  to  think  of  the  best  way  to  prepare  the  batch  or 
mixture.  Where  the  space,  water,  and  power  will  permit,  it  is 


MANUFACTURE   OF   ARCHITECTURAL   TERRA-COTTA.      489 

best  to  run  through  a  washer  a  stated  quantity  of  clay  reduced 
to  a  thick  semi-fluid  condition.  This  by  being  allowed  to  flow 
through  a  long  trough  having  a  broad  flat  bottom,  and  some 
trap  provided,  will  leave  all  stones  and  refuse  behind  in  its  pro- 
gress from  the  washer  to  the  pit  or  pan.  After  this  given 
quantity  of  clay  has  been  sent  to  the  pit,  allow  it  to  stand  for 
awhile  until  the  settlement  of  the  clay  has  allowed  the  water  to 
gather  on  the  top.  A  simple  contrivance  will  form  a  well  in 
one  corner  of  the  pit  into  which  almost  all  the  water  will  run ; 
once  there,  the  water  can  easily  be  drawn  off  by  a  syphon  of 
rubber  tube.  When  the  water  has  been  taken  away,  the  grit 
can  then  be  evenly  scattered  over  the  whole  surface,  and  any 
other  material  which  the  workman  deems  necessary  to  a  good 
terra-cotta  body.  This  alternate  deposit  of  washed  clay  and 
scattered  grit,  etc.,  is  repeated  until  the  pit  is  full,  and  the  whole 
allowed  to  rest  until  it  is  stiff  enough  for  the  pugging  process. 

Another  method,  when  space  is  limited,  is  to  prepare  a  level 
platform  about  25  feet  square,  as  shown  in  Fig.  183,  which  will 
give  a  little  over  600  feet  of  surface,  and  is  capable  of  holding 
50  tons  of  mixed  clay. 

As  soon  as  the  platform  is  ready,  spread  over  it  evenly  forty- 
five  wheelbarrow  loads  of  clay  that  has  been  passed  through 
the  rollers  or  pulverizers,  as  the  case  may  be,  each  load  being 
strike  measure  of  about  300  pounds ;  use  a  standard  size  of 
wheelbarrow  for  all  material,  and  insist  upon  the  workmen  using 
a  striker  to  insure  equal  quantities  in  each  wheelbarrow.  This 
will  save  much  unnecessary  expense  in  weighing  the  different 
materials  used  in  the  mixtures,  and  insure  uniformity. 

When  the  crude  clay  is  leveled  off  to  a  regular  thickness, 
scatter  on  the  top  of  it  the  predetermined  proportion  of  sand 
or  grit.  While  the  grit  is  being  spread  over,  have  a  trustworthy 
man  with  a  hose  and  coarse  sprinkler  pour  on  a  steady  stream 
of  water  sufficient  to  wet  the  mass  ;  this  will  wash  the  grit  down 
into  the  interstices  of  the  clay  lumps,  and  aid  greatly  in  the 
mixing  afterwards.  It  will  be  found  useful  to  mix  at  least  five 
batches,  one  over  the  other  in  each  mixing,  as  this  will  give 


490 


BRICK,  TILES   AND   TERRA-COTTA. 


about  45  tons,  and  it  will  help  to  avoid  differences  or  errors  in 
mixing,  as  it  will  be  certain  that  the  45  tons  will  be  all  alike  if 
care  be  taken  in  moving  it  from  the  platform  to  the  mill,  and 
from  the  mill  to  the  pit.  After  spreading  the  five  batches,  go 
around  the  edge  of  the  mass  and  trim  up  all  the  loose  material, 
throwing  it  upon  the  top  of  the  pile,  taking  care  to  keep  the 

FIG.  183. 


PLATFORM    FOR    MIXING   CLAY. 


top  level.  Then  begin  on  one  side  cutting  square  from  A  at 
the  top  to  B  at  the  bottom,  and  pass  the  mixture  through  a 
pug-mill  regularly ;  then  spread  it  evenly  over  the  surface  of  a 
storage  pit  as  level  as  it  was  before  on  the  platform.  By  this 
process  the  vertical  section  of  the  platform  strata  will  become 
the  horizontal  section  of  the  pit  strata,  and  it  will  be  scarcely 


MANUFACTURE    OF   ARCHITECTURAL   TERRA-COTTA.      491 

possible  for  two  shovelsful  to  come  together  in  the   pit  in  the 
same  relative  positions  which  they  occupied  on  the  platform. 
Fig.  184  represents  five  batches  of  clay  and  grit  laid  up  in 


FIG. 


alternate  layers,  the  whole  being  about  45  tons  of  dry  material. 
A  and  B  indicate  the  directions  of  the  vertical  slice  to  be  cut 
off  in  taking  the  clay  mass  to  the  pit  or  cellar  by  way  of 
the  pug  mill.  The  figures  in  cubes  are  seen  to  lie  in  uniform 
planes,  but  when  the  vertical  section  becomes  the  horizontal 
section  by  lying  in  the  pit  as  described  above,  it  will  be  found 
that  the  cubes  will  be  mixed  as  indicated  in  the  next  cut,  Fig. 
185,  where  A  and  B  form  the  bottom  layer  instead  of  the  end, 
as  in  Fig.  184.  Fig.  185  represents  the  change  of  position  of 
each  cube  after  being  placed  in  the  pit.  This  system  prevents 
either  the  clay  or  grit  from  predominating  in  any  part  of  the 
mass.  The  clay,  after  mixing,  should  remain  at  least  one 
month  in  the  pit  before  tempering  it  in  the  pug-mill. 

There  will  always  be  a  wide  difference  of  opinion  as  to  what 
kind  of  machinery  is  best  suited  to  the  purpose  of  preparing 
clays  and  mixtures  of  clays  and  rendering  them  available  for 
the  use  of  the  terra-cotta  maker. 

It  ought   not  to   be  expected  by  any  practical  clay-worker 


. 


492 


BRICK,  TILES   AND   TERRA-COTTA. 


\f 

that  any  one  machine  should  prove  itself  of  universal  capacity 
and  fitted  to  manipulate  every  description  of  clay. 

There  are  various  and  sufficient  reasons  for  this  difference  of 
opinion : 

First,  clays  differ  very  much  in  particular  qualities :  some 
are  clean,  others  are  stony ;  some  are  tenacious  and  strong, 
others  are  loamy  and  friable ;  some  are  from  deep  alluvial  de- 

FIG.  185. 


posits  and  are  plastic  when  dug,  while  others  are  from  rocky 
formations  and  require  to  be  blasted  when  being  mined,  because 
they  are  in  a  condition  resembling  soft  stone. 

Second, -the  demands  of  the  product  are  as  varied  as  are  the 
qualities  of  clay ;  we  are  only  considering  clays  for  terra-cotta 
work  and  brickmaking,  exclusive  of  those  used  in  the  making 
of  Parian,  porcelain,  china,  and  granite  bodies. 

Clay  that  has  stones  in  it  may  be  used  by  the  maker  of  com- 
mon brick  if  the  stones  are  not  of  a  limestone  formation,  in 
which  case  they  would  be  changed  into  lime  in  the  process  of 
burning,  and  when  the  air  or  water  got  access  to  them  they 
would  burst  and  spoil  the  brick.  Or,  if  rollers  or  crushers  are 
used,  they  may  be  so  reduced  that  they  become  less  objection- 
able. 


MANUFACTURE    OF   ARCHITECTURAL    TERRA-COTTA.      493 

The  maker  of  facing  or  moulded  brick  must  get  rid  of  all 
stones  from  his  clay,  should  any  exist;  therefore  he  has  to  look 
for  a  better  and  cleaner  clay.  He  can  expel  them  by  the  use 
of  a  separator,  or  if  they  are  of  a  quartz  nature  he  may  use  a 
pulverizer  and  reduce  them  to  power,  in  which  case  they  may 
do  more  good  than  harm. 

But  the  terra-cotta  maker  cannot  afford  to  risk  his  product 
by  any  faults  in  his  crude  clays.  He  must  have  as  the  founda- 
tion of  his  stock  a  clean,  tough  clay,  free  from  stone  and  loam, 
so  that  he  may  add  to  it  his  own  proportion  of  grit  or  sand, 
etc.  For  this  reason  he  seeks  for  and  obtains  the  clays  specially 
and  best  suited  to  his  purpose. 

This  may  seem -to  be  an  expensive  method,  but  experience 
will  prove  that  it  is  the  truest  economy.  It  always  pays  to  begin 
right.  He  must  have  clays  of  different  colors ;  some  he  must 
have  brought  to  him  in  any  case  ;  theYefore  he  can  afford  to  pur- 
chase and  freight  a  selection  of  clays,  which  will  give  him  the 
best  results  after  he  has  expended  his  labor  upon  them. 

This  the  brickmaker  cannot  afford  to  do,  for  self-evident 
reasons. 

It  requires  about  four  (4)  tons  of  clay  to  make  one  thousand 
brick;  these  when  burned  will  weigh  about  two-and-a-half 
(2^2)  tons.  These,  if  common  brick,  will  sell  for  from  five  to 
eleven  dollars,  according  to  the  market  and  the  quality.  If  the 
bricks  are  facing  or  moulded  bricks,  they  will  sell  for  from  fif- 
teen to  eighty  dollars  per  thousand,  according  to  the  quality, 
color,  and  design.  Thus,  brick  clay,  when  manufactured  into 
common  brick,  will  produce  only  from  two  dollars  to  three  dol- 
lars and  seventy-five  cents  per  ton,  while  even  the  better  grades 
of  facing  brick  will  produce  only  from  five  to  sixteen  dollars 
per  ton ;  and  even  the  moulded  brick  will  sell  only  for  from 
sixteen  to  thirty  dollars  per  ton.  But  clay,  when  manufactured 
into  terra-cotta,  increases  in  value  far  more  rapidly  in  propor- 
tion to  its  weight.  Four  tons  of  clay  will  produce  three  tons  of 
terra-cotta,  and  the  value  of  terra-cotta-ranges  fron  fifty  dollars 
for  the  commoner  shapes  up  to  two  hundred  for  the  higher 


494 


BRICK,  TILES   AND   TERRA-COTTA. 


grades  of  architectural  work,  and  the  average  value  is  about 
ninety  dollars,  or  more  than  three  times  the  value  of  the  best 
grades  of  moulded  bricks.  This  difference  in  value  in  the  pro- 
duct permits  the  above-described  selection  of  clay  on  the  part 
of  the  terra-cotta  maker,  and  it  at  the  same  time  makes  his 
selection  of  machinery  very  simple,  and  reduces  the  cost  or  ex- 
pense of  plant  and  motive  power. 

The  machines  required  to  furnish  a  very  effective  plant  are 
as  follows : — 

1st.  A  clod-crusher  and  stone-separator. 

2d.  A  stamp-mill  for  breaking  grit. 

3d.  A  bur-mill  for  grinding  grit. 

4th.  A  clay  mixing  pug-mill. 

5th,  A  good  set  of  tempering  pug-mills. 

It  is  impossible  to  say  which  is  absolutely  the  best  machine 
for  any  of  these  purposes,  there  are  so  many,  and  so  many  good 
ones ;  therefore  in  this  chapter  on  clay-working  machinery  only 
those  machines  will  be  mentioned  which  long  and  practical  ex- 
perience has  led  Mr.  James  Taylor  to  adopt  as  best  suited 
for  the  purpose  of  preparing  the  soft  or  plastic  clays  for  the  use 
of  the  terra-cotta  maker. 

They  are  simple,  require  but  a  small  amount  of  power,  have 
few  wearing  parts,  and  can  be  operated  by  any  practical  clay- 
worker. 

The  clod-crusher  and  stone-separator  is  very  necessary  to 
crush  all  lumps  and  to  remove  any  stones  or  foreign  matter 
which  may  by  accident  or  carelessness  have  got  into  the  clay. 

The  Brewer  machine  has  proven  in  practice  to  be  a  very 
satisfactory  one  for  this  purpose. 

The  next  machine  in  order  is  one  for  preparing  the  grit  for 
mixing  with  the  clay  which  has  been  passed  through  the 
crusher. 

For  this  work  there  are  very  many  excellent  machines  in  the 
market,  and  nearly  every  terra-cotta  maker  chooses  a  different 
one. 

Some  use  a  simple  wheel  of  iron,  very  heavy*  revolving  in  an 


MANUFACTURE   OF   ARCHITECTURAL   TERRA-COTTA.      495 

iron  track  or  in  a  pan.  Others  use  the  Blake  crusher  or  some 
similar  form  of  alligator  jaws,  while  some  use  very  powerful 
combined  crushers,  elevators,  and  grinders.  Each  person  sees 
in  the  machine  he  selects  and  purchases  some  special  quality 
that  commends  it  to  his  judgment,  hence  his  selection. 

Mr.  Taylor  for  several  years  used  at  the  Chicago  works  a 
double  set  of  rollers  for  this  purpose,  and  obtained  good  results 
from  their  use  as  crushers,  but  not  as  grinders ;  still,  as  they 
required  too  much  power  to  work  them,  their  use  was  not 
profitable  enough  to  pay  for  repairing  them,  so  when  they  be- 
came worn  they  were  discontinued.  The  stone  breakers  or 
alligator  jaws  are  open  to  the  same  charge ;  they  cost  too  much 
for  power  to  run  them,  are  expensive  at  first,  and  costly  for 
repairs,  so  that  they  are  not  profitable  for  the  terra-cotta 
maker's  use. 

Few  machines  are  profitable  unless  they  can  be  fully  em-* 
ployed.  Powerful  machines  are  costly,  demand  great  power  to 
operate  them,  and  require  much  fuel  to  furnish  that  power. 
If  they  can  be  fully  employed  in  production,  doubtless  they 
yield  great  results  and  are  economical;  but  if  they  have  to 
stand  idle,  it  is  not  good  policy  to  purchase  them. 

For  a  terra-cotta  manufactory  requiring  not  more  than  ten 
tons  of  grit  per  day,  the  most  economical  and  satisfactory  ma- 
chine to  employ  is  a  six  stamp  mill,  with  a  sixteen-inch  drop, 
an  illustration  of  which  is  shown  in  Fig.  186. 

The  next  machine  to  consider  is  the  clay-mixer.  For  this 
purpose  there  are  many,  and  all  of  them  have  some  good  qual- 
ities. The  simplest  one  is  the  old-fashioned  traversing  wheel 
and  pit.  This  is  a  good  mixer,  and  for  soft  mud  is  perhaps  the 
best  all-around  machine.  But  for  the  preparation  of  terra-cotta 
clay,  it  is  important  that  while  the  clay  is  being  thoroughly 
mixed,  it  should  at  the  same  time  be  closely  packed  or  com- 
pressed, so  as  to  expel  as  much  air  as  possible  from  the  clay  or 
body.  This  the  wheel  does  not  do,  therefore  it  is  best  to  use 
a  powerful  pug-mill. 

With  the  clay-mixer  the  list  of  preparatory  machines  is  com- 


496 


BRICK,  TILES   AND   TERRA-COTTA. 


plete.  From  this  machine  the  clay  ought  to  pass  into  storage 
cellars  or  pits,  to  remain  a  sufficient  time  to  allow  of  ^complete 
soaking  or  ripening ;  the  longer  this  period  is,  the  better  for 
the  material. 

When  the  clay  is  required  for  use,  it  is  found  necessary  to 
temper  the  stiff-mud  to  a  proper  consistency,  so  as  to  render  it 

FIG.  1 86. 


SIX-STAMP   MILL. 


easy  to  be  handled  and  pressed  into  the  moulds  which  are  to 
give  it  its  destined  form,  so  that  it  may  take  a  good  impress. 

In  doing  this  it  is  essential  to  have  the  clay  thoroughly 
pugged,  so  that  all  stiff  and  all  sloppy  portions  shall  be  abso- 
lutely intermixed  until  the  whole  is  kneaded  into  a  uniform 
condition  of  stiff  mud.  Should  one  part  be  soft  while  another 


MANUFACTURE    OF   ARCHITECTURAL   TERRA-COTTA.      497 

part  was  stiffer,  the  work  would  surely  crack  and  warp  in  the 
drying,  and  would  scarcely  reach  the  burning  stage.  If  the 
work  should  successfully  pass  through  the  kiln,  it  would  be  so 
unequal  in  size  that  it  would  entail  much  trouble  and  cost,  and 
would  never  be  a  good  specimen  of  the  clay-maker's  skill.  In 
order  to  guard  against  the  carelessness  or  neglect  of  unskilful 
workmen  it  is  a  good  plan  to  insist  upon  a  double  pugging  of 
all  terra-cotta  clays ;  and  to  insure  this  it  is  well  to  use  a  double 
pug-mill,  passing  the  mixture  through  one,  and  then  through 
the  other  immediately  afterwards,  working  both  at  the  same 
time. 

This  double  mill  is  driven  by  a  single  belt  six  inches  wide 
and  of  good  quality. 

As  the  geared  wheels  revolve  in  opposite  directions,  the  mo- 
tion is  very  steady  and  free  from  the  usual  clanging  of  ordinary 
machinery.  .% 

One  man  and  two  boys  can  attend  to  this  mill  and  insure 
good  results.  The  man  shovels  the  clay  into  the  left-hand 
hopper,  and  as  it  passes  out  of  the  orifice  at  the  bottom  of  the 
left-hand  cylinder,  one  boy  catches  the  lumps  and  throws  them 
into  the  hopper  of  the  right-hand  cylinder,  and  as  it  is  forced 
out  at  the  bottom  of  the  right-hand  cylinder  the  second  boy 
catches  it  and  rolls  it  into  blocks  of  about  50  pounds  each; 
these  are  now  ready  to  pass  to  the  presses,  and  any  manufac- 
turer who  will  use  these  methods  will  be  sure  of  preparing 
good  terra-cotta  clay.  The  clay  having  been  properly  pre- 
pared is  next  moulded  or  modeled  into  the  required  design, 
and  if  it  be  a  panel  or  similar  piece  of  work  it  is  turned  out  of 
the  mould  on  to  a  drying-board  to  be  finished  by  retouching, 
undercutting,  and  drying. 

These  drying-boards  are  an  important  part  of  the  furniture 
of  a  terra-cotta  factory,  and  require  to  be  carefully  made. 
They  should  be  strong  enough  not  to  bend  in  the  slightest, 
when  being  lifted  about  by  the  workman,  or  else  the  piece  of 
work  upon  them  is  liable  to  get  broken  by  undue  strain  upon 
some  weak  point.  They  should  be  made  of  white  pine,  as  that 
32 


498 


BRICK,  TILES   AND   TERRA-COTTA. 


wood  is  the  least  liable  to  warp  and  split  under  the  alternate 
wetting  and  extreme  drying  to  which  they  are  subjected  while 
in  use. 

Drying-boards  under  two  feet  long  may  be  made  of  one  inch 
stock  (smaller  ones  of  even  less  thickness)  ;  those  under  three 
feet  long  should  be  one-and-one-quarter  inches  thick,  those 
under  four  feet  should  be  one-and-one-half  inches  thick,  and  all 
over  this  length  should  be  two  inches  thick. 

When  the  drying-boards  are  made  of  strips  six  inches  wide 
secured  to  cleats  of  the  same  size,  the  strips  having  an  open 
joint  three-quarters  of  an  inch,  they  are  less  liable  to  split  and 
warp  in  use  than  when  wider  boards  are  used ;  moreover,  the 
open  joint  permits  the  air  to  circulate  in  the  interior  of  the 
piece  of  work,  and  thus  expel  the  moisture  on  all  sides  at  once. 

FIG.  187. 


DRYING   TERRA-COTTA. 


Figure  187  shows  such  a  piece  of  work  placed  upon  a  dry- 
ing-board such  as  has  been  described,  and  illustrates  a  practical 
method  of  drying  terra-cotta  work  preparatory  for  the  kilns. 

A  rough  bracket,  it  will  be  seen,  has  been  screwed  on  the 
lowed  end  of  the  drying-board  to  permit  it  being  placed  at  a 
sharp  incline  without  allowing  the  piece  of  work  to  slide  off. 

This  incline  is  given  in  order  to  reduce  the  friction  of  the 
clay  upon  the  drying-board,  and  thus  avoid  cracking.  It  is  easy 
to  understand  this  principle ;  the  clay  contracts  as  it  dries,  and 
some  clays  are  not  tenacious  enough  to  draw  their  weight  over 


MANUFACTURE   OF   ARCHITECTURAL   TERRA-COTTA.      499 

so  much  surface  when  laid  level,  but  when  placed  upon  an  in- 
cline, the  material  naturally  falls  into  its  place  during  the  dry- 
ing process.  For  large  pieces  it  is  advisable  to  have  brackets 
at  both  ends  and  alternate  the  incline  daily ;  because  the  lower 
end  has  to  sustain  all  the  weight,  and  is  apt  to  crack  if  not 
sometimes  relieved ;  also  the  top  end  dries  quickest,  so  that  the 
reversing  of  the  ends  tends  to  an  equal  drying  of  all  the  parts. 

It  is  obvious  to  the  most  casual  observer  that  a  panel  of 
clay-work  such  as  is  described  above  has  four  corners  and  four 
lines  of  exposed  edges.  The  four  corners  will  dry  first  because 
they  are  exposed  to  the  air  on  three  sides,  the  upper  edges  will 
dry  next  quickest  because  they  are  exposed  on  two  sides,  while 
the  top  surface  will  dry  slowest  of  all  the  exposed  parts,  because 
it  is  only  acted  upon  by  the  air  on  one  side ;  moreover,  the 
centre  of  such  a  panel  will  dry  more  slowly  because  the  moisture 
is  constantly  being  attracted  from  the  interior.  If  this  panel  is 
placed  upon  the  drying-board  and  left  to  dry,  it  will  surely 
crack  unless  the  clay  is  very  strong,  and  then  it  would  be  likely 
to  warp  badly. 

The  reason  for  this  is  very  simple,  and  is  in  obedience  to  a 
natural  law. 

The  clay,  when  dry,  has  completed  its  shrinkage  so  far  as  it 
can  do  until  fired.  Therefore  as  soon  as  the  corners  are  dry 
they  cease  to  contract ;  then  the  exposed  edges  still  continue  to 
contract,  moving  most  in  the  direction  of  the  centre,  because 
they  dry  from  the  corner  toward  the  centre,  the  result  being 
that  the  edges  are  all  curved  inward  when  dry,  from  the  efforts 
of  the  mass  to  contract  toward  the  common  centre  of  the  panel. 

The  edges  having  completely  dried,  in  turn  like  the  corners 
cease  to  recede,  but  the  entire  central  surface  has  considerable 
shrinkage  to  perform  yet,  and  there  is  no  avoiding  it;  until  dry 
it  must  shrink,  and  as  the  corners  and  edges,  having  done  their 
part,  have  become  rigid,  the  centre  can  only  shrink  by  breaking 
loose  somewhere,  hence  the  cracks  so  often  found  in  large 
pieces  of  work  during  the  process  of  drying. 

The  remedy  for  this  is  to  guide  the  elemental  movement.     It 


500  BRICK,  TILES   AND   TERRA-COTTA. 

is  possible  to  direct,  even  if  we  cannot  oppose,  natural  forces. 
By  covering  the  edges  and  corners  of  such  a  panel  with  a  light 
rubber  cloth  (which  can  be  bought  for  twenty-five  cents  per 
yard),  and  leaving  about  one-third  of  the  upper  surface  of  the 
centre  only  exposed,  the  centre  can  be  made  to  dry  first;  then 
the  edges  will  contract  upon  the  centre,  drying  from  the  centre, 
and  the  result  will  be  a  sound  and  perfect  form.  The  raising 
of  this  drying-board  to  an  incline  not  only  reduces  the  friction, 
but  it  also  allows  the  air  to  pass  freely  through  the  open  joints 
of  the  drying-board  into  the  cells  and  back  side  of  the  panel, 
and  thus  aids  in  an  equable  drying  of  the  whole  mass.  This 
principle,  with  modifications  to  suit  the  particular  shape, 
weight,  and  bulk  of  the  pieces  being  made,  will  insure  success 
in  the  making  of  any  piece  of  clay  work  that  it  is  practicable  to 
make.  Successful  drying  demands  constant  watchfulness. 

In  any  factory  that  employs  steam  as  a  motive  power  for  its 
machinery,  steam  piping  will  furnish  the  best  and  safest  heating 
for  the  purpose  of  warming  the  shops  and  drying  the  work  in 
process  of  manufacture. 

The  steam  pipes  should  be  hung  over  head,  about  one  foot 
below  the  ceiling  or  lower  edge  of  the  next  story  floor-beams, 
and  should  consist  of  numerous  single  lines  of  one-inch  pipe 
connected  with  a  four-inch  header  at  both  inlet  and  outlet,  care 
being  taken  to  allow  ample  escape  for  the  exhaust-steam,  so  as 
to  avoid  any  back  pressure  upon  the  engine. 

The  pipes  should  be  placed  in  the  second  section  of  beams 
from  the  wall,  and  the  floor  over  the  pipes  should  be  laid  with 
open  joints  of  half  an  inch.  This  enables  the  entire  section  of 
the  floor  next  the  windows  to  be  used  for  working  near  the 
light,  and,  of  course,  there  the  floor  is  tight-jointed,  and  should 
be  double  with  paper  between  to  prevent  dust  and  water  leak- 
ing through. 

The  finished  work  is  set  on  the  open-jointed  portion  of  the 
floor,  and  is  thus  in  a  constant  but  gentle  circulation  of  air,  which 
enables  it  to  dry  equally,  and  without  cracking  or  warping. 

After  the  work  is  dry  enough,  it  is  moved  toward  the  central 


MANUFACTURE    OF  ARCHITECTURAL  TERRA-COTTA.       501 

sections  of  floor,  which  also  is  tight-jointed  and  double,  to 
await  its  removal  to  the  kilns. 

There  is  no  necessity  for  either  steam-pipe  heat  or  open  floor 
in  the  kiln-end  of  the  building,  as  it  will  be  found  that  the  kilns 
themselves,  when  in  constant  operation,  will  ventilate  and  heat 
the  workshops,  and  dry  the  work  made  in  that  portion  of  the 
factory. 

In  addition  to  the  above,  there  should  be  a  circuit  of  steam 
piping  for  live  steam,  to  be  used  in  extreme  cold  weather  only. 
This  should  be  placed  at  about  seven  feet  six  inches  from  the 
floor  and  three  feet  from  the  outer  walls,  and  encircle  all  the 
space  not  warmed  by  the  action  of  the  kiln  heat.  The  posi- 
tion, of  course,  can  be  varied  to  suit  any  other  conditions,  but 
in  a  building  such  as  is  described  this  would  be  the  method  to 
adopt,  and  the  circuit  would  be  a  direct  one ;  the  top  story 
only  requiring  three  lines  of  pipe*,  the  next  lower  one  line 
of  pipe  more,  and  so  on  until  the  first  floor  is  reached ;  this 
would  thus  require  six  lines  of  pipe,  which  would  give  ample 
heat  at  a  low  pressure  of  steam. 

The  question  of  drying  the  clay  forms,  after  they  are  taken 
from  the  moulds,  and  preparing  them  for  the  kiln,  is  also  one 
that  must  be  governed  by  some  general  rules,  but  these  rules 
can  only  be  observed  subject  to  the  special  case  of  the  several 
forms  of  clay  work  produced.  It  is  possible  to  state  some 
method  that  will  apply  generally  to  the  drying  of  simple  forms, 
such  as  brick  and  pottery,  which  are  of  universal  shape  and 
bulk ;  but  in  case  of  architectural  terra-cotta  work,  which  varies 
so  exceedingly  in  its  size,  shape,  and  bulk  of  material,  no  spe- 
cific method  can  be  stated  so  as  to  be  of  universal  application. 

The  rules  to  be  observed  are  simple  and  few.  First,  avoid 
too  violent  a  draught  of  air.  Second,  reduce  the  friction  of 
drying  clay  upon  the  drying  board  as  much  as  possible,  and 
third,  dry  uniformly. 

Extreme  draughts  of  air  cause  the  external  surfaces  to  dry 
too  rapidly,  and  the  result  is  warping  and  cracking.  The  weight 
of  clay  in  a  piece  of  terra-cotta  work  is  often  greater  than  the 


502  .  BRICK,  TILES   AND   TERRA-COTTA. 

tenacity  of  the  clay  is  able  to  move  in  proportion  to  the  shrink- 
age, hence  cracks  in  the  weak  parts  of  the  form  which  is  being 
dried. 

Unequal  drying  of  the  parts  also  produces  warping  and 
cracking. 

Suppose  a  piece  of  work  has  to  be  made  three  feet  long,  by 
two  feet  wide,  and  six  inches  thick :  this  should  be  moulded  of 
a  uniform  thickness  of  one-and-a-half  inches,  with  cross  parti- 
tions about  six  inches  apart  each  way  in  its  interior  or  back 
side,  such  partitions  being  only  one  inch  in  thickness,  and  care 
being  taken  to  make  a  circular  hole  in  each  section  of  the  par- 
titions to  allow  of  a  free  circulation  of  air  among  the  cells  thus 
formed  in  the  body  of  the  piece  of  work. 

BURNING. 

The  muffle  terra-cotta  kilns,  as  used  by  the  New  Jersey  com- 
panies, are  extremely  simple  in  their  construction,  of  which 
Fig.  1 88  gives  a  correct  elevation;  see  also  frontispiece. 

The  kilns  are  up-draft  in  principle,  and  provided  with  short 
high  furnaces  arranged  for  anthracite  coal  as  fuel.  There  is  a 
double  door,  the  upper  one  resting  upon  piers,  thereby  form- 
ing alleys  and  flues.  In  the  centre  is  a  communicating  chimney 
that  connects  with  the  hollow  floor  space,  carrying  heat  from 
the  furnace  under  the  floor  and  up  through  the  center  of  kiln, 
whence  it  escapes  through  the  center  hole  in  main  crown  into 
dome,  not  to  be  utilized  any  further. 

The  principal  heat  rises  directly  from  the  furnaces  into  the 
flue  surrounding  the  muffle,  then  under  the  main  crown  over 
the  muffle  crown  to  the  center  outlet  into  the  dome. 

The  regulation  of  the  heat  under  the  floor  and  through  the 
center  of  the  kiln  is  by  closing  and  opening  more  or  less  the 
flue  spaces  leading  from  the  furnaces  to  underneath  the  floor 
and  center  chimney.  The  draft  of  kiln  is  effected  by  regulat- 
ing the  opening  in  main  crown  in  dome  by  means  of  a  fire  clay 
tile. 

The  kilns  are  invariably  round  in  shape.     The  inside  meas- 


MANUFACTURE   OF   ARCHITECTURAL  TERRA-COTTA.      503 

urements  are  12  feet  diameter  and  12  and  20  feet  high.  The 
muffle  flues  are  6  inches,  mufflle  tiles  being  2J^  inches  thick. 
Some  of  the  furnaces  have  open  fires,  as  shown  in  Fig.  189, 
while  others  are  provided  with  doors,  as  in  Fig.  188.  The 
burning  quality  of  the  kilns  is  good,  but  they  are  wasteful  of  fuel. 

FIG.  188. 


MUFFLE   TERRA-COTTA   KILN. 

The  kilns  as  built  by  the  two  works  in  Boston  differ  some- 
what in  construction,  as  will  be  seen  in  elevation  and  section 
of  Figs.  189  and  190.  Some  of  them  are  built  round  and  some 
oblong.  Their  size  varies  <from  10  to  12  and  13  feet  in  diameter, 
by  9  to  17  feet  in  height.  The  muffle  flues  are  from  4^2  to  5j4 
inches  spacing ;  thickness  of  muffle  varies  from  two  to  three 
inches.  In  circulation  of  heat  they  are  up  and  down  draft;  the 
heat  rising  upward  into  the  muffle  flue,  over  the  muffle  crown, 
and  downward  through  the  centre  flue  (or  chimney),  then 


504 


BRICK,  TILES   AND   TERRA-COTTA. 


under  the  floor,  and  from  there  the  heat  passes  upward  in  flues 
built  between  the  furnaces  in  the  muffle  space,  then  leads  into  the 
dome  on  side  of  kiln.  The  number  of  furnaces  to  a  kiln  are  six 


FIG.  189. 


FIG.  190. 


TERRA-COTTA  KILNS. 


and  seven.  All  the  kilns  are  built  with  projecting  top  feeders, 
arranged  for  anthracite  coal,  which  is  being  used  exclusively  as 
fuel. 

These  kilns  do  good  work,  and  are  more  economical  in  the 
consumption  of  fuel  than  the  direct  up-draft  as  used  by  the  New 
Jersey  companies. 

The  muffle  kilns  adopted  by  western  works  differ  in  many 
ways  from  those  of  eastern  manufacturers,  ranging  from  12  to 
24  feet  in  diameter,  and  from  9  to  22  feet  in  height,  and  are, 
without  question,  superior  to  those  used  in  the  east. 

The  Northwestern  Terra-Cotta  Company  of  Chicago  adopted 
two  styles  of  muffle  kilns — direct  down-draft  and  up-and-down 
draft.  They  claim  that  the  latter  are  giving  better  results  in 
even  burning  and  a  slight  saving  of  fuel.  The  fuel  used  is 
Indiana  block  coal,  also  called  Brazil  block.  This  coal  is  very 


MANUFACTURE    OF   ARCHITECTURAL   TERRA-COTTA.       505 

rich  in  carbon  and  very  free  burning,  much  resembling  Scotch 
machine  coal,  except  that  it  is  harder  and  can  be  cut  and  split 
like  slate.  It  makes  a  clear,  mild  fire,  like  that  of  oak  wood. 
Fuel,  of  course,  has  much  to  do  with  the  good  working  of  a 
kiln.  It  is  reasonably  certain  that  with  an  anthracite  coal  that 
lies  quiet  in  the  furnace,  producing  a  less  lively  fire,  a  less  per- 
fect circulation  or  distribution  of  heat  will  be  effected  than  by 
using  a  coal  carrying  a  decided  flame,  thereby  having  a  farther 
calorific  effect.  Of  course,  in  building  kilns,  the  requirements 
of  mechanical  science  are  far  different  than  for  building  a  brick 
house.  Some  masons  think  that  in  bricklaying  all  brick  bonds 
are  the  same.  This  may  do  for  the  inexperienced,  but  it  can. 
be  readily  understood  that  in  a  wall  that  is  exposed  to  a  con- 
tinuous action  such  as  expansion  and  contraction,  the  wear  and 
tear  is  very  destructive  in  comparison  with  the  undisturbed 
masonry  in  a  building  of  different  character  and  purpose.  In 
a  good  kiln  three  qualifications  are  essential :  good  combus- 
tion, even  circulation  of  heat,  and  durability  of  construction. 
The  building  of  kilns  should  not  be  left  to  inexperienced  per- 
sons, as  they  represent  the  principal  part  of  the  capital  of  a 
well  established  works. 

One  of  the  hardest  colors  to  obtain  uniformity  in  the  tint  is 
the  elegant  buff,  and  to  secure  this  rich,  pleasing  color  in  terra- 
cotta, requires  long  burning,  and  a  highly  experimental  knowl- 
edge of  firing,  as  well  as  a  thorough  acquaintance  with  the  clay, 
and  its  behavior  in  the  kiln. 

FUELS    FOR   TERRA-COTTA. 

Coal  should  not  be  used  in  firing  light-colored  terra-cotta, 
as,  although  the  usual  products  of  combustion  are  separate 
from  the  ware,  sulphurous  fuel  darkens  and  tarnishes  the  sur- 
face. Wood  should  be  used  in  burning  light-colored  terra- 
cotta ;  but  for  red  or  darker-colored  ware  no  objection  should 
be  urged  against  the  use  of  coal. 

Kilns  for  burning  terra-cotta  are  generally  circular  in  form, 
and  are  expressly  built  so  as  to  obtain  a  greater  degree  and 


506  BRICK,  TILES   AND   TERRA-COTTA. 

better  distribution  of  heat  than  can  possibly  be  obtained  in  an 
ordinary  open  brick-kiln.  A  perspective  view  of  terra-cotta 
kilns  is  shown  in  the  frontispiece  of  this  volume. 

The  principle  of  applying  the  heat  in  terra-cotta  kilns  by  the 
overdraft  system  is  much  approved.  In  these  kilns  the  heat  is 
carried  to  the  top  through  flues  in  the  walls,  and  the  kiln  being 
covered,  and  the  draft  toward  the  bottom,  the  heat  descends 
through  the  ware. 

In  this  class  of  kilns  the  stock  is  not  so  liable  to  crack,  break, 
warp,  and  twist,  as  in  the  Hoffman  and  other  annular  con- 
structed kilns. 

But  the  principal  gain  in  the  circular  overdraft  kilns  is  the 
impartial  and  equable  distribution  of  heat,  thereby  securing  a 
greater  uniformity  in  the  color  of  the  terra-cotta,  which,  in  ad- 
dition to  the  saving  mentioned,  makes  such  kilns  very  desirable. 

The  usual  time  required  for  burning  terra-cotta  is  from  five 
to  seven  days,  which  is  "dependent  upon  the  condition  of  the 
ware  when  it  is  set  into  the  kiln,  as  well  as  upon  the  purposes 
for  which  it  is  required. 

IMPROVEMENT  IN  THE  CONSTRUCTION  OF   TERRA-COTTA  KILNS. 

The  object  of  the  arrangement  shown  in  Figs.  191  to  193  is 
to  modify  the  construction  of  the  doors  of  kilns  for  burning 
terra-cotta  in  such  a  way  that  the  heat  will  be  distributed  equally 
through  the  door  and  the  other  parts,  so  that  all  of  the  kiln  will 
have  a  uniform  temperature. 

The  invention  is  that  of  Mr.  Afred  Hall,  of  Perth  Amboy, 
N.  J.,  a  gentleman  who  has  spent  a  lifetime  in  the  manufacture 
of  terra-cotta,  and  it  consists  in  so  arranging  a  door  for  terra- 
cotta kilns,  with  flues  in  its  inner  part,  communicating  with  and 
forming  continuations  of  the  ordinary  flues  in  the  kiln-wall,  and 
connected  with  the  furnaces  by  flues,  that  a  uniform  distribution 
of  heat  all  around  the  kiln  will  be  effected,  and  all  the  articles 
in  the  kiln  will  receive  an  equal  degree  of  heat,  and  thereby  be 
burned  more  satisfactorily  than  is  usual. 

Fig.  191   is  a  front  elevation  of  the  improvement,  shown  as 


MANUFACTURE   OF   ARCHITECTURAL   TERRA-COTTA.       507 


applied  to  a  kiln.  Fig.  192  is  a  sectional  plan  view  of  the  for- 
ward part  of  the  kiln.  Fig.  193  is  a  sectional  elevation  of  the 
door. 

A  represents  the  furnace  doors,  B  the  ash-pits,  and  C  the 
door  of  the  kiln  D.     To  the  side  parts  of  the  door  frame  are 

FIG.  191. 


FIG.  193. 

attached  plates  £,  which  project  at  the  sides  of  the  door,  and 
have  eyes  formed  in  their  outer  ends  to  receive  pins  F.  The 
pins  F  also  pass  through  holes  in  the  ends  of  the  U  bars  or 
clevises  G,  between  which  ends  the  eyes  of  the  plates  E  are 
placed.  The  bends  of  the  bars  G  pass  also  through  eyes  in  the 
forked  ends  of  the  right  and  left  screws  L.  The  screws  L  pass 
through  right  and  left  screw-holes  in  the  ends  of  the  bars  M, 
which  cross  the  door  C,  and  have  a  longitudinal  slot  formed 
through  them  to  receive  a  lever,  so  that  they  can  be  turned  to 


508  BRICK,  TILES   AND   TERRA-COTTA. 

draw  the  screws  L  inward  and  firmly  clamp  the  door  C  in  place. 
With  this  construction  the  door  C  can  be  removed  by  remov- 
ing the  pins  K,  the  screws  Z,  and  the  bars  M. 

In  the  inner  part  of  the  door  C  are  formed  flues  /,  which, 
when  the  door  is  closed,  communicate  with  and  form  continua- 
tions of  the  ordinary  flues  J  in  the  inner  parts  of  the  kiln  walls. 
With  this  construction  the  inner  part  of  the  door  and  the  inner 
wall  of  the  kiln  will  be  heated  perfectly,  so  that  there  will  be 
no  cool  part  of  the  kiln,  as  the  products  of  combustion  from 
the  furnaces  A  are  introduced  into  the  flues  7  of  the  door  C 
through  flues  a  in  the  same  manner  as  they  are  introduced  into 
the  flues  J  in  the  inner  wall  of  the  kiln,  so  that  the  heat  will 
be  distributed  evenly  all  around. 

MODELING   TERRA-C01TA. 

Considering  the  fact  that  this  is  a  great  time  for  the  revival 
of  lost  or  neglected  arts,"  it  is  not  surprising  that  modeling  of 
terra-cotta  should  have  been  given  a  high  place,  It  is  a  kind 
of  work  eminently  adapted  for  amateurs,  and  those  who  con- 
template making  a  business  of  clay  working,  and  we  do  not 
hesitate  to  commend  it  to  them,  in  the  belief  that  faithful  and 
conscientious  workers  will  reap  a  rich  and  abundant  harvest  as 
the  fruit  of  their  labors.  In  the  earliest  ages  this  sort  of  model- 
ing was  much  practiced;  then  came  sculpture;  but  that  art  de- 
pended on  modeling,  as  it  does  now,  for  its  excellence. 

The  process  of  manipulating  terra-cotta  is  not  essentially  dif- 
ferent from  that  of  other  clay.  Care  should  be  taken  in  the 
selection  of  the  model.  Bearing  in  mind  that  it  is  easier  to 
x  copy  a  large-sized  head  than  a  small  one,  for  the  reason  that 
Uhe  lines  of  the  former  are  longer,  deeper,  and  require  less 
minute  work,  the  amateur  should  choose  some  fair-sized 
plaster  of  Paris  cast  as  his  first  model.  Very  good  specimens 
can  be  procured  of  almost  any  cast-maker  at  a  low  rate.  As 
the  worker  progresses  in  the  art  it  will  be  well  to  copy  works 
of  representative  masters,  many  of  which  are  well  worthy  of 
imitation,  whether  for  the  excellence  of  the  work,  the  faithful- 


MANUFACTURE   OF   ARCHITECTURAL   TERRA-COTTA.       509 

ness  of  the  model,  or  the  patience  and  scientific  knowledge  dis- 
played in  their  construction.  From  this  the  transition  to 
copying  from  life  is  easy;  for,  although  in  the  latter  work  a 
greater  experience  in  drawing  is  required,  and  some  familiarity 
with  geometry  and  anatomy  is  necessary,  it  is  not  so  difficult 
as  may  be  imagined. 

The  materials  are  few  in  number  and  inexpensive,  which  lat- 
ter fact  will  score  a  long  point  in  its  favor  with  many  amateurs, 
especially  those  who  undertake  the  work  merely  as  an  experi- 
ment The  material  consists  of  a  modeling  stool,  a  hollow  flat 
box,  a  few  boxwood  tools  of  various  shapes  and  sizes,  and  the 
terra-cotta  clay,  which  may  be  obtained  ready  for  use,  and 
which  will  keep  for  months. 

If  the  subject  be  a  head,  the  process  is  as  follows :  Take  the 
flat  box  and  screw  an  upright  piece  of  wood  firmly  through  its 
middle  and  let  it  pass  through  the  h«le  of  the  modeling  stool 
that  is  made  to  secure  it.  This  will  also  support  the  bust  while 
it  is  in  a  moist  state.  The  clay  is  then  piled  around  the  wood 
after  having  been  wetted  and  well  kneaded  to  prevent  it  being 
hempy  and  streaky,  and  cracking  while  it  is  drying.  Work 
the  clay  compactly  and  firmly  around  the  base  of  the  up- 
right first,  and  then  pile  it  up  to  the  required  height  of  the  bust 
and  knead  it  well  with  the  fingers,  which  should  be  kept  moist 
to  prevent  the  clay  from  sticking  to  them.  The  clay  will 
settle  and  it  may  possibly  fall  down  after  being  left,  and 
must  be  rebuilt,  but  this  little  trial  will  not  occur  after  the  sec- 
ond working.  Form  the  clay  into  the  rough  form  of  the 
bust,  and  having  measured  the  height  and  widths  of  the  model, 
work  the  clay  to  match  its  proportions,  using  the  fingers 
for  the  purpose.  Then  model  the  features  roughly,  and  block 
in  the  hair  in  broad  masses. 

This  being  done,  the  first  day's  work  is  finished  and  the  terra- 
cotta should  be  enveloped  in  a  wet  cloth,  which  must  be  kept 
moist.  This  may  easily  be  done  by  sprinkling  it  with  a  florist's 
syringe,  which  is  a  much  better  plan  than  removing  it.  Some 
judgment  is  required  in  this,  as,  if  kept  too  wet,  terra-cotta  will 


5IO  BRICK,  TILES   AND   TERRA-COTTA. 

not  bear  shaping  with  the  fingers  and  tools,  and  if  allowed  to 
get  too  dry  it  will  invariably  crack  and  spoil  the  work. 

The  second  day's  work  consists  in  shaping  the  features, 
which  is  best  done  with  a  wet  rag  wrapped  around  the  forefin- 
ger. All  the  features  must  be  gone  over  and  carefully  worked 
up,  and  the  head  and  hair  completely  formed,  the  lines  of  the 
hair  being  finished  with  the  modeling  tools.  A  little  terra- 
cotta clay  softened  to  the  consistency  of  cream  will  be  found 
useful  to  apply  to  any  parts  that  require  smoothing. 

When  the  work  is  finished  and  nearly  hard  it  should  be  pol- 
ished. This  is  accomplished  by  taking  a  piece  of  fine  leather, 
soaking  it  in  water  and  rubbing  it  gently  over  the  bust  until  the 
result  is  attained. 

Modeling  terra- cotta  from  the  clay  is  very  fascinating  work, 
and  not  difficult.  A  fair  knowledge  of  drawing  is  of  course 
necessary.  A  good  stock  of  patience  and  perseverance  will 
also  be  required  to  achieve  anything  like  satisfactory  results, 
but  the  game  is  worth  the  candle. 


CHAPTER  XV. 

ORNAMENTAL  TILES,    ETC.* 

SOME  years  ago  a  learned  Italian  found  in  an  old  library  in 
the  city  of  Florence  a  manuscript  of  the  fifteenth  century  on 
the  Art  of  Painting,  in  which  the  author  traces  the  history  of 
the  art  back  to  the  common  father  of  mankind,  and  from  Adam 
to  God  Himself,  thereby  seeking  to  prove  that  the  art  was 
divine  and  coeval  with  the  very  creation  of  man. 

Although  we  cannot  claim  so  high  an  origin  or  go  back  quite 
so  far  with  the  history  of  tiles,  nevertheless  we  can  positively 
state  with  truth  that  wherever  we  find  historic  man  we  are  sure 
to  find  tiles  of  one  kind  or  another.  In  fact,  among  the  most 
ancient  documents  we  have,  are  records  kept  upon  clay  tablets, 
which  are  nothing  more  nor  less  than  tile  books.  I  allude  to 
the  Chaldean  and  Assyrian  tablets  found  in  such  numbers  amid 
the  ruins  of  Mesopotamian  palaces,  and  from  which  the  Assyro- 
Chaldean  student  has  been  able  to  add  many  pages  to  the  his- 
tory of  the  primitive  civilization  of  man. 

That  tiles  are  found  so  universally  under  every  form  of  civi- 
lization and  in  every  age  is  not  to  be  wondered  at,  when  we 
remember  that  they  are  made  of  clay,  a  substance  found  in  all 
lands,  cheap,  plastic  in  its  nature,  yielding  readily  to  the  hand 
of  man,  and  becoming  fixed  by  the  sun's  heat  or  by  fire,  and 
that  they  lend  themselves  under  their  numberless  forms  not 
only  to  many  practical  ends,  but  also  to  the  highest  require- 
ments of  decorative  art.  So  we  find  tiles  used  as  records,  floors, 
walls,  roofs,  ceilings,  tombs,  baths,  altars,  pulpits,  altar  pieces, 

*  Partly  from  an  article  by  Caryl  Coleman  published  in  the  Decorator  and  Furnisher 
New  York. 


512  BRICK,  TILES   AND   TERRA-COTTA. 

friezes,  dados,  fire-places,  hearths,  wainscots,  table  tops,  drains, 
stoves,  grills,  balconies,  and  in  many  other  ways. 

The  higher  the  art  culture  of  a  people,  the  greater  their  use 
of  tiles.  For  this  reason  we  hear  so  often  now-a-days  about 
tile,  when  so  much  thought  is  given  to  the  decorative  arts  and 
cultivation  of  artistic  taste.  A  few  years  ago  they  were  almost 
unknown  in  the  United  States,  while  to-day  there  are  many  tile 
makers  and  thousands  of  dollars  invested  in  the  business,  and 
yet  the  demand  is  greater  than  the  supply  both  for  domestic 
and  imported  goods ;  therefore  it  seems  to  me  it  is  high  time 
that  the  general  public  should  be  made  acquainted  with  the 
history  of  tile  and  its  use  in  the  past  as  a  decorative  medium. 

The  first  thought  or  question  that  naturally  arises  is :  What 
is  a  tile?  To  get  a  true  definition  we  must  first  consider  the 
origin  of  the  English  word  "tile."  It  is  derived  from  the  Latin 
noun  tegula,  and  that  is  formed  from  the  verb  tegere,  to  cover, 
and  was  used  by  the  Romans  to  name  a  piece  of  baked  or  dried 
clay  used  for  covering  houses ;  hence  a  tile  is  all  forms  of  baked 
clay,  glazed  or  unglazed,  plain  or  decorated,  which  is  used  to 
cover,  or  is  applied  upon  another  body  or  object  such  as  a 
roof,  a  floor,  or  wall,  etc.  Before  1840  all  tiles  were  plastic, 
being  made  from  wet  clay ;  since  that  date  the  larger  part  have 
been  made  from  clay  reduced  to  dust  and  formed  into  a  tile  by 
pressure. 

There  are  two  great  families  of  tiles,  unglazed  and  glazed. 
The  unglazed  are  subdivided  into : 

Plain,  a  bisque  tile  of  one  color. 

Inlaid,  a  tile  where  one  colored  clay  is  forced  into  another 
color. 

Indented,  a  tile  with  the  designs  depressed  below  the  face. 

Relief,  a  tile  with  a  design  standing  above  the  face. 

Printed,  a  tile  with  a  design  printed  in  color  upon  its  face. 

Glazed  tiles  are  divided  in  their  turn  as  follows :  vitreous  or 
glass-glazed,  plumbeous  or  lead-glazed,  stanniferous  or  tin- 
glazed,  and  are  again  subdivided  into : 

Plain,  a  tile  faced  with  a  transparent  glaze  and  depending  for 
its  color  on  the  bisque  or  body  showing  through  the  glaze. 


ORNAMENTAL   TILES,  ETC. 


513 


Enameled,  a  tile  having  the  face  covered  with  a  colored 
glaze. 

Incised,  a  tile  with  a  design  cut  through  the  glaze  down  to 
the  body  or  bisque. 

Indented,  a  tile  with  a  design  scratched  or  stamped  upon  the 
clay  body  and  covered  with  a  glaze. 

Relief,  a  tile  with  a  design  modeled,  pressed,  or  stamped 
above  the  face  or  back-ground  and  covered  with  a  glaze. 

Painted,  a  tile  with  a  design  painted  upon  the  bisque  and 
then  glazed,  or  a  tile  with  the  painting  upon  the  glaze  itself. 
In  the  first  case  called  underglaze,  and  in  the  last  overglaze 
work. 

Printed,  a  tile  with  a  design  printed  on  the  bisque  and  then 
glazed. 

The  oldest  tile  makers  that  we  have  any  historical  knowledge 
of  were  unquestionably  the  Egyptian*,  who  not  only  made  tiles 
to  decorate  their  buildings  with,  but  also  for  inlaying  wood  and 
bronze  objects ;  however,  as  with  us,  their  greater  use  was  in 
architecture,  in  cases  wjiese  beauty  of  decoration  was  required. 

FIG.  194. 


This  latter  application  of  tiles,  with  the  Egyptians,  commenced 
at  a  very  early  period  in  their  history.  The  inner  doorway 
(Fig.  194)  of  the  pyramid  at  Laggara  was  covered  with  glazed 
tile  of  a  most  beautiful  blue,  the  face  slightly  convexed,  and 
33 


5H  BRICK,  TILES   AND   TERRA-COTTA. 

having  on  the  back  a  pierced  tenon  (Fig.  195).     The  color  of 
these  tile  is  truly  remarkable,  a  most   delicate  celestial    blue 

FIG.  195. 


glaze,  obtained  from  a  pure  and  very  white  sand,  soda,  and  the 
oxide  of  copper. 

In  the  brick  temple  of  Ramses  III.,  built  1228  years  before 
the  Christian  era,  tiles  were  used  in  great  numbers  on  the  walls 
and  floors,  around  the  doorways,  and  upon  the  outer  walls. 

FIG.  196. 


Some  of  the  tiles  were  in  relief,  the  body  or  background  in  blue 
or  yellow  bisque,  with  figures  modeled  upon  it  in  colored  pastes, 


ORNAMENTAL   TILES,  ETC. 


515 


the  garments  on  the  figures  of  the  men  in  various  flat  colors, 
the  faces,  limbs  and  hair  glazed  in  appropriate  tints  (Figs.  196, 
196  A,  196  B).  The  Egyptians,  in  common  with  Assyrians, 
used  round  inlaid  vitrified  tiles  of  white  on  blue,  or  the  reverse, 
for  the  ornamentation  of  walls  (Fig.  197),  sometimes  massed 
together,  but  oftener  as  string  courses  and  for  giving  a  riveted 
effect  to  their  walls.  Like  the  Assyrians,  but  not  so  generally, 
they  wrote  upon  tile  tablets,  not  by  incising  the  characters  upon 
an  unglazed  tile,  but  like  the  modern  Chinese  school-boy  writes. 


FIG.  196  A. 


FIG.  196  B. 


FIG.  197, 


them  with  black  ink.     That  the  Jews  used  tiles  for  the  same 
purpose  we  know  from  the  words  of  the  prophet  Ezekiel  iv.  I  : 

"And  thou,  O  son  of  man,  take  thee  a  tile  and  lay  it  before  thee,  and  draw  upon 
it  the  plan  of  the  city  of  Jerusalem." 

The  Babylonians  and  Assyrians  carried  the  art  of  tile  making 
and  their  application  both  for  practical  and  artistic  purposes, 
to  a  much  higher  point  than  the  Egyptians,  and  in  fact  than 
any  other  of  the  ancient  nations. 

Their  glazes  are  brighter  and  finer,  their  range  of  color 
greater,  and  their  forms  more  numerous.  One  of  their  most 
novel  forms  was  a  cone-shaped  tile,  three  and  a  half  inches 
long,  of  a  yellow  body,  having  its  base  dipped  in  color  and 
its  apex  running  to  a  sharp  point  (Fig.  198).  These  tiles 
were  not  only  fixed  to  flat  walls,  but  also  to  curved  surfaces,. 


516 


BRICK,  TILES    AND   TERRA-COTTA. 


the  apex  being  imbedded  in  cement,  the  colored  base  turned 
outward  and  arranged  in  patterns  of  various  designs  (Fig.  199). 
The  tiles  of  Chaldea  were  in  part  bas-relief,  obtained  by  pil- 
ing on  the  color  or  enamel,  while  on  the  other  hand  the  Assyr- 
ian tiles  were  flat,  with  the  single  exception  of  their  round  tiles, 
which  were  used  in  vast  numbers  about  doorways  and  the 


FIG.  198. 


FIG.  199. 


upper  parts  of  walls,  the  central  boss  being  in  low  relief  (Fig. 
200). 

In  Assyria,  pictures  and  geometric  designs  of  large  size  were 
executed  upon  the  walls  of  temples  and  palaces  by  uniting  tiles, 
on  each  of  which  a  portion  of  the  general  pattern  was  made 
(Fig.  201).  The  ceiling' tiles  were  of  diverse  forms — round, 
square,  square  with  concave  edges — but  in  all  cases  having  a 
round  hole  in  the  center,  through  which  a  pin  or  boss  of  metal 
or  ivory  could  be  passed  to  hold  them  securely  in  their  place 
(Fig.  202). 


ORNAMENTAL  TILES,  ETC. 


517 


The  prevailing  colors  in  the  glaze  tiles  were  blue,  red,  a  deep 
yellow,  white,  green,  black,  gold  and  silver,  while  the  unglazed 
or  floor  tiles  were  but  of  two  colors,  a  dark  red  and  a  yellowish 
white. 

The  extreme  gorgeousness  of  the  tile-incrusted  buildings  of 


FIG.  200. 


FIG.  20 1. 


Assyria,  as  they  flashed  forth  their  beauty  under  a  brilliant 
oriental  sun,  is  hard  to  picture  to  our  minds,  accustomed  as  we 
are  to  the  colorless  architecture  of  the  present  day.  Is  there 
not  a  lesson  to  be  learned  here?  Should  we  not  be  more  bold 
in  our  use  of  color,  not  only  for  interior  but  also  for  exterior 
decoration?  No  doubt  color  will  be  used  more  freely  among 
us  when  our  architects  are  properly  educated,  when  they  be- 
come not  only  good  constructors  but  have  also  a  knowledge  of 
artistic  proportion,  harmony  of  design,  and  the  decorative 
principle  governing  the  use  of  materials  in  their  relations  of 
color  and  texture  to  the  whole  structure  and  to  one  another. 

Among  the  practical  uses  that  tiles  were  put  to  in  Babylonia 
(626  B.  C.  to  522  B.  C.)  was  that  of  a  circulating  medium.    The 


5  1 8  BRICK,  TILES   AND   TERRA-COTTA. 

tiles  used  were  four  and  a  half  inches  in  length  by  one  to  three 
inches  in  breadth,  with  their  value  in  gold  or  silver,  the  name 
of  the  reigning  king,  and  the  date  of  issue  inscribed  on  their 
face. 

Very  little  is  known  about  the  tiles  of  the  Jews  and  Phoeni- 
cians— so  little,  that  some  archaeologists  have  doubted  if  these 
people  used  them  to  any  great  extent. 

Among  the  Greeks  tiles  were  used  in  large  numbers,  that  is, 

FIG.  202. 


the  unglazed  kind,  for  tombs,  for  roofs  and  floors,  pediments 
and  friezes ;  as  to  their  glazed  tiles  we  know  little  or  nothing. 
How  far  they  carried  the  art  of  tile  making  it  is  hard  to  say, 
although  we  know  from  their  writers  and  the  examples  of  their 
other  pottery  that  they  must  have  attained  a  high  standard. 

With  the  Etruscans  tiles  were  principally  used  to  line  the 
walls  of  tombs.  The  tiles  were  large,  forty  inches  long  and 
twenty  inches  wide,  with  figures  and  inscriptions  painted  on 
them  in  red,  black  and  white,  and  burnt  in  the  tile  (See  Fig. 
203). 

The  Romans  inherited   the   art   of   tile   making    from  their 


ORNAMENTAL   TILES,  ETC. 


519 


Etruscan  forefathers,  and  also  used  them  as  they  did  for  tombs, 
but  more  commonly  on  the  walls  and  roofs  of  their  houses ; 
these  tiles  were  sometimes  scale-shaped,  sometimes  oblong, 
oftener  flanged ;  in  color  they  were  of  a  rich  red  and  bright 
yellow.  The  floor  tiles  were  made  in  small  cubes  of  various 
colors  and  were  set  in  patterns. 

With  the  fall  of  the  Roman  empire,  the  art  of  tile  making, 
like  all  other  arts,  passed  under  a  cloud,  but  only  for  a  while, 

FIG.  203. 


for  it  was  brought  to  life  again  by  the  Mohammedans  in  the 
East  and  the  Monks  in  the  West,  to  shine  with  greater  splen- 
dor than  ever  before. 

The  development  of  tile  making  in  the  United  States  has  been 
the  most  remarkable  instance  of  rapid  progress  of  an  industry 
of  any  country  or  age,  and  our  tile  makers  may  be  relied  upon 
to  hold  the  place  they  have  gained  against  all  the  competition 
of  Europe. 

Scarcely  two  years  after  the  Centennial  Exposition,  Mr.  John 
G.  Low,  of  Chelsea,  Mass.,  commenced  the  erection  of  a  tile- 
factory  in  his  native  place.  Less  than  a  year  and  a  half  after 


520 


BRICK,  TILES   AND   TERRA-COTTA. 


the  works  were  started  we  find  the  firm  competing  with  English 
tile  makers  at  the  exhibition  at  Crewe,  which  was  conducted 
under  the  auspices  of  the  Royal  Manchester,  Liverpool,  and 

FIG.  204. 


ORNAMENTAL   TILES,  ETC. 


52I 


North  Lancaster  Agricultural  Society.  They  won  the  gold 
medal  for  the  best  collection  of  art  tiles  exhibited.  This  record 
serves  to  illustrate  the  remarkably  rapid  development  of  an  in- 

FIG.  205. 


dustry  new   in  America,  but  old  in  the   East,  and  shows  the 
resources  at  command  of  the  American  potter. 

In    1883,  Mr.  John  F.  Low,  son  of  the  founder,  became  as- 
sociated with  his  father  under  the  style  of  J.  G.  &  J.  F.  Low. 


522  BRICK,  TILES   AND   TERRA-COTTA. 

These  works  make  stove  tiles,  calendar  tiles,  clothes-hooks, 
paper-weights,  inkstands,  and  pitchers  in  plain  colors,  enameled 
and  glazed.  Lately  they  have  been  making  a  specialty  of  the 
manufacture  of  art-tile  soda  fountains,  specimens  of  which  are 
shown  in  Figs.  204  and  205. 

The  Beaver  Falls  Art  Tile  Company,  Limited,  of  Beaver 
Falls,  Pa. ;  the  Providential  Tile  Works,  Trenton,  N.  J. ;  the 
Trent  Tile  Company,  Trenton,  N.  J. ;  the  Cambridge  Art  Tile 
Works,  Covington,  Ky. ;  and  the  Menlo  Park  Ceramic  Works, 
Menlo  Park,  N.  J.,  are  also  engaged  in  the  manufacture  of  art 
tiles. 

In  the  production  of  printed,  inlaid,  and  relief  tiles,  America 
has  advanced  rapidly,  but  in  the  production  of  hand-painted 
art  tiles  she  is  as  yet  deficient.  This  is  a  branch  of  the  art 
that  must  be  developed  through  the  influence  of  our  mechan- 
ical art  schools,  which  are  paving  the  way  for  an  early  revolu- 
tion in  ceramic  industry  in  the  United  States. 

Our  designers  saw  much  at  the  Columbian  Exposition  in 
1893  to  start  them  to  thinking,  and  when  the  present  industrial 
depression  shall  have  passed  away  there  will  be  brought  out 
many  new  and  artistic  designs  in  art  tiles. 

The  process  of  creating  from  clay  those  exquisite  creations 
in  decorative  design  known  as  art  tiles  was  explained  to  me  by 
Mr.  Lawshe.  The  tile  factory  is  on  the  outskirts  of  Trenton,  N.  J. 

Mr.  Lawshe  conducted  me  to  the  yard,  where  a  lot  of  cars 
stood  on  a  railroad  track  loaded  with  creamy-colored  clay  or 
chalk.  It  was  dumped  by  a  couple  of  chalk-begrimed  work- 
men into  big  sheds  not  unlike  coal  bins,  only  much  larger. 

"This  is  where  the  first  step  toward  making  tiles  is  taken," 
said  my  conductor.  "  The  chalk  is  in  this  box ;  it  is  called 
spar.  This  is  nothing  more  or  less  than  flint  (taking  up  a 
handful  of  powered  stuff  from  another  compartment).  Just 
hard  flint  rock  ground  to  a  powder.  This  chalk  and  flint,  which 
•come  from  Great  Britain,  Maine,  Virginia  and  Tennessee,  are 
mixed  in  proper  proportions  and  dumped  into  the  mill,  where 
it  is  ground  up  and  run  through  a  series  of  sieves  to  extract  all 
grit  and  foreign  substances." 


ORNAMENTAL   TILES,  ETC.  523 

Following  the  directions  of  Mr.  Lawshe,  the  writer  observed 
that  from  the  mill,  which  looks  like  a  big  grist  mill  seen  in 
flouring  mills,  only  larger,  the  material  was  conveyed  to  an 
enormous  vat,  where  it  was  mixed  with  Delaware  river  water 
until  it  assumed  the  consistency  of  a  big  caldron  of  the  Irish 
national  dish,  "stir-about." 

From  this  vat  the  stir-about  was  quickly  pumped  into  a  series 
of  wooden  molds  about  six  feet  long  and  two  feet  deep.  Each 
mold  held  a  heavy  duck  bag  which  exactly  fitted  its  inside, 
through  which  the  water  and  the  stir-about  would  seep,  while 
the  immense  hydraulic  pressure  was  exerted  to  bring  them 
together  and  the  water  was  all  squeezed  out.  Releasing  the 
molds,  they  were  laid  flat-wise  and  open.  The  bags  were  deftly 
turned  back,  exposing  to  view  a  six-foot  section  of  chalk  which 
looked  just  like  a  big  apple  dumpling  after  being  "  undressed  " 
and  ready  to  be  placed  on  the  table  piping  hot.  Really  it  looked 
appetizing,  but  the  old-fashioned  boat  of  brandy  sauce,  which 
our  grandmothers  knew  so  well  how  to  make,  was  missing. 
The  two  workmen  looked  like  fat,  well-fed  cooks  themselves. 
The  dumpling  was  seized  and  quickly  rolled  into  a  big  cruller, 
with  the  jelly  left  out,  of  course,  and  thrown  into  a  long  drying 
trough,  whence,  after  becoming  dry,  it  was  conveyed  into  the 
main  building  and  broken  into  small  bits,  this  time,  strangely 
enough,  assuming  the  appearance  of  a  big  pile  of  broken  stale 
bread. 

This  stale  bread  or  "wad,"  was  next  run  through  another 
mill,  and  still  another.  From  the  last  mill  the  wad  came  out  as 
fine  and  free  from  grit  as  a  box  of  lady's  toilet  powder,  and  dry 
as  a  bone.  An  endless  elevator,  with  ever-moving  cups, 
caught  the  powder  up  as  it  fell  from  the  hopper  and  lifted  it  to 
the  next  floor  above,  where  it  lay  in  bins  ready  to  be  pressed 
into  tiles. 

Following  our  pudding,  not  up  the  elevator,  but  the  more 
convenient  stairway,  my  conductor  halted  me  by  a  heavy 
stamping  machine,  operated  by  a  red-cheeked  youth  of  eighteen 
years,  who  was  deftly  scraping  and  putting  little  piles  of  the 


524  BRICK,  TILES   AND   TERRA-COTTA. 

now  slightly  dampened  powder  into  a  mortise  let  into  the  steel 
bed  of  the  machine.  This  machine  looks  like  ordinary  stamp- 
ing machines  used  in  notaries'  offices,  only  about  a  hundred 
times  bigger.  The  mortise  which  the  youth  was  filling  was 
about  nine  inches  square  and  seemingly  two  or  three  inches 
deep.  Filling  it  to  the  level,  he  knocked  off  the  superfluous 
chalk  and  touched  a  pulley  that  set  the  machine  in  motion. 
Slowly,  slowly,  a  massive  ponderous  rod  of  burnished  steel  be- 
gan to  descend,  and  the  powder  was  crushed  into  a  solid  cake 
of  clay  by  a  pressure  of  eighty  tons.  Then  the  bar  shot  back 
and  became  stationary,  while  the  young  man  handed  the  writer 
the  newly  made  tile  to  inspect.  On  the  reverse  side  was  the 
trade  mark  of  the  maker,  while  on  the  face  was  a  clear  and 
beautifully  executed  profile  of  Editor  Stearns,  of  the  American 
Artisan.  It  was  an  exact  counterfeit  of  that  gentleman  in 
plaster  cast — a  bas-relief.  The  process  is  just  the  same  as  is 
followed  in  stamping  gold  eagles  in  the  mint,  and  the  young 
man  at  the  machine  turned  out  the  counterfeits  faster  than  the 
writer  could  lay  them  in  a  neat  pile. 

At  another  machine  a  pretty  young  woman  with  rich  ripe  lips 
and  suggestively  plump  arms,  was  manufacturing  fac-similes  of 
a  maiden  twenty-four  inches  long,  whose  brevity  of  drapery,  if 
anything  which  does  not  exist  may  possess  "  brevity,"  would 
make  "  Iza"  Johnstone  turn  green  with  envy  and  send  Anthony 
Comstock  scooting  off  to  get  an  injunction  and  a  piece  of  gauze. 

From  the  stamping-room  my  conductor  led  me  to  the  die- 
room,  where  all  the  dies  for  the  myriad  of  exquisite  decorative 
tiles  are  taken.  All  these  dies  are  cut  intaglio,  and  the  most 
expert  workmanship  is  required.  The  workmen  receive  high 
wages  and  their  hours  of  labor  are  short. 

The  modeling-room  was  next  visited  and  the  writer  was  in- 
troduced to  Mr.  Wm.  W.  Gallimore,  the  father  of  American 
Belleek  ware,  the  finest  and  most  expensive  porcelain  in  the 
world.  Mr.  Gallimore  extended  his  left  hand. 

"You  must  excuse  his  left  hand,"  said  Mr.  Lawshe,  "he  has 
only  one." 


ORNAMENTAL   TILES,  ETC.  525 

"  Your  loss  does  not  seem  to  interfere  with  you  much,"  I 
ventured. 

"  No,  I  do  not  miss  it  much  now.  But  let  me  show  you  how 
a  model  is  made,"  and  picking  up  a  nine-inch-square  block  of 
what  looked  like  plaster-of-Paris,  he  began  laying  on  little 
pieces  of  dirty  dough.  While  thus  engaged  he  continued  chat- 
ting, occasionally  looking  up  at  the  writer.  Now  and  then  he 
would  pinch  the  dough  up  in  one  place  with  his  finger  or  press 
it  down  in  another  with  a  little  steel  instrument  which  he  held 
between  his  ringers. 

"  Just  stand  there  ;  that's  right;  don't  move  your  head  now," 
and  with  a  satisfied  smile  he  went  on  with  his  pinching,  and 
flattening  out  process  until  I  saw  a  reproduction  of  myself. 

Thus  mollified,  I  was  led  to  the  dipping  room  (that's  my 
term  for  it),  where  a  score  of  pretty  girls,  with  sleeves  rolled 
up,  were  dipping  the  faces  of  the  pressed  tiles  into  pans  of 
what  looked  like  colored  milk.  One  saucy-looking  miss  was 
having  lots  of  fun  ducking  a  famous  Egyptian  Queen  into  a 
pan  of  chocolate-colored  milk  and  laying  her  side  by  side  on  a 
shallow  vessel  to  dry.  Another  motherly-looking  woman  with 
soft  expressive  eyes  and  gray  hair,  was,  with  genuine  tender- 
ness, giving  a  sweet-faced  little  cherub  of  10  years  a  bath  in 
pink  milk;  while  a  dashing -looking  Irish  girl,  with  a  roguish 
brogue,  was  sousing  jolly  old  Bacchus  deep  into  a  bowl  of 
mixed  ale  and  porter,  which  the  old  fellow  seemed  to  like  im- 
mensely. He  was  unable  to  consume  it  all,  however,  and  it 
trickled  down  his  abundant  beard  upon  his  capacious  chest. 

Still  further  on  a  girl  of  eighteen  was  daintily  dabbing  the 
smooth  faces  of  her  tiles  with  several  different  colors,  transform- 
ing some  into  chalcedony,  others  into  onyx,  both  Californian 
and  Mexican,  marble  and  granite,  and  other  handsome  stone 
effects.  Only  they  did  not  look  like  these  things  just  then.  This 
was  the  glazing  room,  and  the  milk-pans  contained  liquid  glass 
into  which  different  chemicals  had  been  stirred  to  produce  the 
variety  of  colors  required.  The  girls  worked  rapidly,  and  as 
fast  as  the  tiles  were  dipped  they  were  borne  in  the  direction 


526  BRICK,  TILES   AND   TERRA-COTTA. 

of  the  furnaces,  where  they  were  submitted  to  the  process 
known  as  "  firing." 

This  is  almost  the  last  stage  in  the  manufacture  of  a  tile, 
though  one  of  the  most  delicate,  and  in  some  respects  the  least 
understood.  The  tiles  are  placed  in  large  porous  earthen  ves- 
sels, called  setters  among  the  potters  who  make  pots  and  cups. 
The  setter  is  rilled  with  tiles  and  a  lid  placed  on  it.  Then  a 
piece  of  common  red  Jersey  clay  two  feet  long  is  used  to  her- 
metically seal  the  setters.  The  setters  are  then  placed  in  the 
kiln,  one  on  top  of  another,  from  the  floor  to  the  ceiling.  The 
door  of  the  kiln  is  then  closed  and  the  fires  are  started.  Care 
must  be  taken  to  lay  the  tiles  perfectly  level  in  the  setters,  and 
also  to  make  a  similar  disposition  of  the  setters  in  the  kiln.  A 
perfect  disposition  of  the  "glost"  on  the  face  of  the  tile  can 
only  be  secured  thus :  Should  a  tile  tip  the  slightest  portion  of 
a  degree  the  lower  edge  will,  after  "  firing,"  be  found  to  be 
much  darker  than  the  upper  edge,  which  will  be  very  light. 
This  is  due  to  the  law  of  nature  which  causes  the  liquid  glaze 
to  seek  its  level.  If  one  will  take  the  trouble  to  examine  a 
handsome  tile  panel,  say  of  a  pastoral  scene,  it  will  be  observed 
that  the  sheep  in  the  foreground,  standing  out  almost  white, 
are  in  bas-relief,  while  those  dark  ones  on  the  brow  of  the  dis- 
tant hill  are  intaglio.  The  dark  shades  surrounding  the  young 
shepherd — himself  almost  pure  white — are  simply  slight  con- 
cavities into  which  the  glaze,  liquefied  by  the  heat,  has  flowed. 
In  a  word,  no  artist  is  required  to  produce  the  exquisite  shad- 
ing so  often  met  with  in  the  higher  class  of  tiles — you  lay  on 
the  colors,  the  fire  does  the  rest. 

From  the  kiln  the  product  is  ready  to  go  to  the  packing 
room,  where  all  imperfect  pieces  are  rejected,  and  the  different 
styles  are  assorted  and  packed  in  barrels  ready  for  shipping. 

The  manufacture  of  tiles  in  this  country  was  an  unknown 
industry  thirty  years  ago.  To-day  nine-tenths  of  the  tiles 
used  in  America  are  made  in  Trenton  and  Cincinnati.  The  art 
of  making  tile  24  to  30  inches  long  and  6  to  15  inches  wide  in 
one  solid  piece,  is  a  New  Jersey  discovery  which  foreign  makers 


ORNAMENTAL  TILES,  ETC.  527 

cannot  imitate.  The  advantage  of  this  is  apparent  in  inspect- 
ing the  panels,  one  made  in  a  solid  piece  and  the  other  in  two 
or  three  sections.  The  glaze  on  the  solid  panel  will  be  found 
all  of  one  shade ;  but  let  the  maker  of  the  three-section  panel 
be  never  so  careful,  he  will  never  succeed  in  producing  an  exact 
similarity  of  shades  on  the  three  pieces.  The  effect  of  this  is 
less  harmonious  than  the  single  piece.  When  Europe  fur- 
nished all  the  tiles  used  in  this  country,  Americans  paid  $1,250 
per  thousand  feet  for  the  plainest  tile,  and  much  larger  prices 
for  the  artistic  panels.  Now  $250  to  $350  is  the  price  for  the 
plain  product,  while  artistic  patterns  are  proportionately  low. 

It  may  be  a  matter  of  interest  to  readers  to  know  that  one 
of  the  most  valuable  discoveries  ever  patented  for  making 
patent  tiles  is  the  property  of  a  bright  young  woman,  Miss 
Frye,  a  school  teacher,  who  will  soon  be  able  to  desert  the 
school-room  and  live  on  the  royalty  *of  her  patent.  Just  what 
this  patent  is  the  writer  is  not  at  liberty  to  tell,  but  like  every- 
thing truly  feminine,  it  is  lovely  and  simple.  It  is  something 
every  male  potter  has  been  trying  to  discover  for  many  years 
— a  lost  art  in  fact — and  every  blessed  man  who  has  seen  it  has, 
man-like,  exclaimed  :  "  What  a  blankety  idiot  I  was  not  to  have 
thought  of  it."  You  see,  the  only  thing  to  do  was  to  think  of 
it;  the  balance  was  easy  enough.  However,  nobody  ever 
thought  of  it  till  Miss  Frye  had  the  patent  safe  in  her  pocket, 
and  along  with  it  a  handsome  fortune  in  prospect  and  a  com- 
petency for  the  present.  Like  all  really  studious  and  thinking 
women,  Miss  Frye  is  modest  to  a  degree,  and  reticent  as  to 
herself  and  her  discovery. 

There  is  also  a  fortune  awaiting  the  man  who  will  rediscover 
the  lost  art  of  producing  the  green,  blue  and  red  of  the  ancients 
from  copper ;  the  first  two  colors  can  be  got  easily  enough,  but 
the  last  is  delusive.  Will  the  "man"  who  finds  this  be  a 
"woman"  also? 

Various  tile  machines  have  been  designed  for  the  manufac- 
ture of  tiles  from  dust  or  semi-dry  clay,  but  we  are  unable  here 
to  reproduce  more  than  one.  Fig.  206  shows  a  screw  press, 


528 


BRICK,  TILES   AND   TERRA-COTTA. 


made  by  Mr.  Peter  Wilkes,  of  Trenton,  N.  J.,  for  the  Trent  Tile 
Company,  and  will  give  an  excellent  idea  of  the  principle  on 
which  the  majority  of  such  machines  are  operated.  This  forms 
tiles  six  inches  to  twelve  inches  square,  the  die  being  placed 


FIG.  206. 


between  the  "  push-up  "  and  "  plunger."     It  can  also  be  used 
for  making  plates,  oval  dishes,  and  other  ware. 

In  France  great  attention  is  at  present  paid  to  the  manufac- 
ture of  glazed  or  enameled  tiles  (tuiles  vernissees  ou  encaus- 
tiques).  The  guiding  points  in  glazing  the  tiles  are  either  a 
white  coating  with  the  subsequent  use  of  a  colorless  glaze,  or  a 
colored  coating  with  a  subsequent  coat  of  a  colored  glaze.  In 
the  first  case  the  white  coating  is  simply  a  layer  of  white  or 


ORNAMENTAL  TILES,  ETC.  529 

refractory  clay,  and  the  colorless  glaze  is  either  applied  to  the 
crude  but  perfectly  dry  product,  which  requires  only  one  burn- 
ing, or  upon  the  biscuit,  which  requires  two  burnings.  In  the 
second  case  the  preparation  of  the  colored  coatings  is  effected 
in  the  same  manner  as  that  of  the  colored  masses,  by  mixing 
the  coloring  oxides  previously  triturated,  melted  and  fritted  to- 
gether with  an  antiplastic  substance,  such  as  quartz,  sand  or 
feldspar,  with  white  clay ;  the  application  is  effected  the  same 
as  colorless  coatings. 

If  the  glaze  is  laid  upon  a  coating  it  will  always  present  a 
brilliant  and  beautiful  appesrance,  free  from  cracks,  while  if 
directly  applied  to  the  mass  it  will  always  have  a  dull  look. 
The  latter  method,  to  be  sure,  is  cheaper,  and  favored  by  the 
action  of  a  hot  sun,  is  chiefly  employed  in  Southern  France, 
while  the  damp  and  dull  northern  part  allows  only  of  glazing 
upon  biscuit. 

As  regards  the  glazes  themselves  they  may  either  be  free 
from  lead  or  contain  it. 

Glazes  free  from  lead  are  prepared  by  fritting  and  subse- 
quently grinding  the  following  constituents  : 

Common  salt,  40  parts ;  saltpeter,  22 ;  potash,  22 ;  pow- 
dered glass,  1 6.  On  account  of  its  slight  content  of  silica,  this 
glaze  is  suitable  for  masses  containing  sand. 

On  the  other  hand,  for  a  strongly  clayey  mass  or  one  con- 
taining marl,  the  following  mass,  ground  and  fritted,  is  very 
suitable  on  account  of  its  high  content  of  silica : 

Saltpeter,  20  parts ;  potash,  20 ;  pulverized  glass,  20 ;  pul- 
verized silex,  20;  common  salt,  10;  clay,  10. 

To  those  two  formulae,  taken  from  Bronguiart,  we  add  two 
methods  according  to  Chaptal : 

Dip  the  articles  to  be  glazed  in  a  dilution  of  Marviel-earth 
and,  after  drying,  repeat  the  manipulation  in  water  containing 
porphyrized  glass.  In  burning  the  constituents  fuse  to  an 
earthy  alkaline  colorless  glaze. 

According  to  the  second  method,  dip  the  well-dried  articles 
in  a  very  strong  solution  of  common  salt,  and  burn.  The  sili'co- 
34 


530 


BRICK,  TILES   AND   TERRA-COTTA. 


alkaline  glaze  formed  requires  a  mass  containing  silica  for  the 
formation  of  the  silicate  with  the  common  salt. 

In  the  following  table  we  give  glazes  containing  lead,  the 
bases  being  lead  monosulphide  or  galena  (alquifour)  and  min- 
ium or  red  lead. 


Color  of  the  glaze. 

Glaze  containing  lead. 

Parts. 

Minium  glaze. 

Parts. 

{: 

80 

Minium  

67 

White  sand  

12 

White  sand  

u/ 

2A 

White  clay  

3 

White  clay    

{' 

Galena  

78 

Minium  ..........    .. 

61 

7° 
II 

White  sand  

UO 

27 

g 

\Vhite  clay 

, 

Galena  

78 

Minium  

60 

Sand                .... 

/** 

10 

Brown  

White  clay    

6 

OJ> 

2 

Oxide  of  manganese.  .  . 

3 

f 

77 

58  6 

Sand    

'£ 

->2  7 

White  clay  

6 

6^'S 

4.6 

1 

Oxide  of  manganese.  .  . 
Sulphate  of  copper  .... 

3 
3 

Sulphate  of  copper  .... 
Black  oxide  of  cobalt  .  . 

2.3 

2.3 

0.04 

76 

67 

White  sand  

12 

White  sand  

2* 

White  clay    

6 

White  clay    

Sulphate  of  copper  .... 

6 

Sulphate  of  copper  .  .  . 

5 

Galena  

81  o 

665 

White  sand  

12.2 

White  sand  

23.9 

6  c 

White  clay    

Q  1 

Black  oxide  of  cobalt  .  . 

"O 

0.3 

Black  oxide  of  cobalt  .  . 

0-3 

The  cheaper  galena,  as  compared  with  the  more  expensive 
minium,  has  the  disadvantage  of  yielding,  with  the  same  weight, 
one-half  less  glaze,  and  hence  is  in  the  end  as  costly ;  on  the 


ORNAMENTAL   TILES,  ETC.  531 

other  hand,  it  is  not  nearly  so  dangerous  as  regards  the  poison- 
ing of  the  workmen. 

The  manufacture  of  colored  glaze  tiles,  as  carried  on  in 
Munich  and  its  vicinity,  where  it  is  very  skillfully  done,  is  much 
imitated  in  France.  A  brief  sketch  of  the  Munich  process 
may,  therefore,  be  of  interest. 

The  mass  prepared  with  great  care  consists  of  one  volume  of 
potter's  clay,  one-half  volume  of  red  clay,  and  one  volume 
quartz  sand,  or  one  volume  marl  and  one  volume  quartz  sand, 
the  following  composition  of  glaze  or  enamel  being  especially 
suitable  for  this  mixture.  Great  attention  is  also  paid  to  the 
working  of  the  glaze  composition.  The  separate  constituents 
are  very  finely  ground  dry  and  then  treated  with  water.  The 
composition  consists  of  twelve  parts  by  weight  of  lead-ashes, 
four  of  lithargyrum,  three  of  quartz  sand,  four  of  white  alumina, 
two  of  common  salt,  three  of  powdered  glass  and  one  of 
saltpetre. 

Flat  tiles  having  been  carefully  dried  and  strongly  burned 
are,  previous  to  glazing,  placed  for  two  days  in  water  to  free 
the  surface  from  impurities  acquired  in  burning  and  to  slake 
the  lime  which  may  be  contained  in  them. 

For  the  purpose  of  glazing,  the  constituent  parts  of  the  glaze 
are  sifted,  thoroughly  mixed  and  vitrified  in  glass  pots.  The 
glass  thus  obtained  is  finely  ground,  with  the  admission  of 
water,  in  a  mill,  and  in  this  state  employed.  By  adding,  prior 
to  the  preparation  of  the  lead-ashes,  twenty  to  twenty- five 
pounds  of  tin  to  every  100  pounds,  the  whiteness  is  considera- 
bly increased. 

For  the  production  of  colored  enamel  to  be  applied  with  the 
brush,  add  to  every  100  pounds  of  enamel  mass  the  following 
substances,  sifted  and  finely  ground,  whereby  the  respective 
colors  are  obtained.  By  greater  or  smaller  deviations,  all 
imaginary  shades  can  be  produced.  For 

Golden  yellow 5.12    Ibs.  of  antimony. 

Pale  blue °-3°5  IDS«  red  ox.  of  cobalt. 

Violet « 2.500  Ibs.  red  manganese. 


532  BRICK,  TILES   AND   TERRA-COTTA. 

Deep  brown  violet 5.000  Ibs.  red  manganese. 

Red 3-75°  Iks.  red  manganese. 

Green 2.500  Ibs.  copper  ash. 

Black o.  100  Ibs.  lithargyrum. 

"     0.050  Ibs.  manganese. 

In  the  manufacture  of  enameled  tiles,  lead-poisoning  some- 
times occurs.  The  great  principles  to  be  observed  in  all  works 
where  lead  is  used,  are  the  inculcation  of  cleanliness ;  avoiding 
eating  with  unwashed  hands,  or  in  working-clothes,  or  in 
work-shops ;  moist  grinding ;  free  ventilation ;  precautions 
against  dust  raising,  or  wearing  of  flannel  respirators  when  dust 
is  unavoidable ;  and  occasional  doses  of  sulphate  of  magnesia 
acidulated  with  sulphuric  acid.  Sulphuric  acid  lemonade  has 
been  recommended  as  a  drink. 

In  acute  lead-poisoning  from  any  cause,  the  stomach  must  be 
emptied  by  the  stomach-pump,  or  by  emetics — of  which  sul- 
phate of  zinc  is  to  be  preferred.  Solutions  of  the  alkaline  or 
earthy  sulphates — of  which  the  best  is  sulphate  of  magnesia — 
are  indicated,  with  the  view  of  forming  the  comparatively  in- 
soluble sulphate  of  lead,  and  expelling  it  from  the  intestines. 

Workmen  who  begin  to  show  signs  of  lead-poisoning  should 
at  once  give  up  the  work,  and  take  to  some  other  employment. 

THE    MANUFACTURE   OF    CLAY- DUST   TILES    HAVING    SURFACES    IN    RELIEF    OR 

INTAGLIO. 

Fig.  207  is  a  plan  of  a  tile  with  an  intaglio  figure  thereon, 
representing  its  use  as  a  mould.  Fig.  208  is  a  plan  of  a  tile 
with  a  figure  in  relief  thereon,  also  representing  its  use  as  a 
mould.  Fig.  209  is  a  cross-section,  illustrating  the  manner  of 
their  use.  Mr.  Low,  the  inventor  of  this  process,  uses  a  plastic 
material,  like  paraffine,  and  places  it  in  the  tile-frame  of  the 
tile-compressing  machine,  and  subjects  it  to  pressure,  thus  pro- 
ducing a  flat  thin  plastic  plate  of  about  the  thickness  of  a  tile ; 
or  he  takes  a  quantity  of  clay-dust  and  similarly  compresses  it, 
and  saturates  this  dust  with  paraffine.  The  upwardly- 
presenting  surface  of  this  plate  is  then  plentifully  sprinkled 


ORNAMENTAL  TILES,    ETC. 


533 


with  pulverized  plumbago,  which  is  compressed  into  the  sur- 
face of  the  plate. 

The  compressed  plate  may  now  be  engraved  with  any  de- 
sired pattern,  care  being  taken  to  cover  it  with  black-lead 
powder,  brushed  on  with  naphtha,  or  any  other  solvent  of 
paraffine  as  a  vehicle,  or  dusted  on  to  a  slightly-warmed  sur- 
face, or  stippled  on  with  a  stippling- brush.  The  parts  denuded 


FIG.  207. 


FIG.  208. 


FIG.  209. 


$$ 

s§ 

by  engraving  can  be  used  as  an  electrotype  mould  to  make  a 
reverse,  and  the  electrotype  used  as  a  matrix  to  make  an  ob- 
verse. These  electrotypes,  well  backed,  as  when  used  for 
printing,  and  set  in  steel  or  other  strong  boxes  to  prevent  crush 
of  the  backing,  will  serve  as  dies  for  making  the  intaglios  and 
reliefs  for  stamping  tile  in  dry-clay  dust. 

In  case  high  reliefs  are  desired,  the  paraffine  (or  better,  the 
clay  and  paraffine)  plate  may  be  carved,  as  desired,  carefully 
avoiding  under-cutting,  and  then  covered  with  its  plumbago 
surface,  by  the  naphtha  process  or  stippling,  and  electrotyped 
and  used  as  the  die. 

When  high  reliefs,  which  it  is  desirable  to  undercut,  are  to 
be  made,  the  mould  is  made  so  that  the  compressed  clay  will 


534  BRICK,  TILES   AND   TERRA-COTTA. 

draw,  and  the  main  part  of  the  design  being  thus  formed,  the 
modeler  carves  the  undercutting  by  hand,  the  clay  being  suf- 
ficiently tenacious  when  compressed  to  allow  this,  and  the 
finished  tile,  partly  hand-made  and  partly  machine-made,  is 
then  fired. 

For  obtaining  textures,  low  reliefs,  or  intaglios  of  natural  ob- 
jects, and  the  like,  the  inventor  may,  if  he  desires,  use  the 
paraffine  plate  made,  as  has  been  described  above,  with  plum- 
bago surface,  for  electrotyping ;  but,  instead  of  engraving  it,  he 
forms  an  impression  in  its  black-leaded  surface  by  the  objects 
he  wishes  to  represent,  in  the  manner  hereafter  described  for 
unleaded  paraffine  or  clay-dust.  It  is  preferable,  however,  as 
it  gives  great  variety  in  design  with  slight  expense,  to  adopt 
the  following  manipulation :  Having  formed  the  compressed 
plate,  as  already  described,  raise  in  the  tile-frame  of  the  tile- 
machine  the  lower  platen  till  the  upper  surface  of  the  com- 
pressed plate  is  conveniently  near  the  top  of  the  frame,  and 
compose  upon  the  surface,  by  laying  thereon  bits  of  woven 
stuff,  lace,  pieces  of  embossed  paper,  leather,  or  other  fabric, 
leaves,  grasses,  flowers,  or  other  objects  having  suitable  textures 
and  outlines,  such  a  design  as  will  be  attractive ;  then  lower  the 
platen  to  place,  and  bring  down  the  plunger  with  strong  com- 
pression upon  the  objects.  By  this  means  they  are  indented 
in  outline  and  texture  in  the  plastic  or  clay-dust  surface,  even 
overlays  being  represented  with  an  accuracy  absolutely  true  to 
nature,  and  always  intaglio. 

As  already  said,  this  intaglio  may  be  used  as  a  mould  for 
electrotypes,  when  properly  made,  by  the  use  of  pulverized 
plumbago  as  a  surfacing  agent ;  but  the  inventor  usually  takes 
this  matrix  so  made,  and  places  over  it  a  diaphragm  of  thin, 
tough  material — a  rubber  film  will  serve,  and  many  other  ma- 
terials ;  but  the  best  and  cheapest  is  the  thin  Japanese  paper, 
of  uniform  texture  and  great  toughness,  such  as  appears  in  the 
Japanese  handkerchiefs  and  napkins,  so  called.  This  dia- 
phragm must  exactly  cover  the  surface  of  the  intaglio.  Upon 
it  is  next  laid  the  dust  of  surface  and  body-clay  of  the  tile  to 


ORNAMENTAL   TILES,  ETC.  535 

be  embossed,  which  is  subjected  to  compression  in  the  ordinary 
way,  and  thereupon,  on  raising  the  plunger  and  platen,  the  in- 
taglio and  relief  may  be  separated,  the  diaphragm  peeled  by 
aid  of  a  sharp  tool  to  start  it  from  the  die,  usually  the  relief,  to 
which  it  generally,  if  not  always,  adheres,  and  the  intaglio  will 
usually,  with  proper  care  in  handling,  be  found  perfectly  unin- 
jured during  several  hundred  impressions. 

When  the  surface  is  of  one  clay  and  the  body  of  another, 
each  clay  is  to  be  separately  compressed,  unless  sgraffito  effects 
are  desired,  in  which  case  the  surface-layer  must  be  carefully 
applied,  so  as  not  to  cover  the  pattern  desired  to  be  of  the 
color  of  the  body-  clay. 

The  sharpness  and  definition  of  texture  of  reliefs  made  from 
dust-clay  intaglios  are  very  remarkable,  and  tile  compressed 
from  dust  from  its  homogeneous  quality  is  much  less  likely  to 
warp  or  shrink  unevenly  in  firing  ^han  any  other,  particularly 
if  packed  in  a  less  fusible  powder,  like  quartz  grains  or  canister 
in  firing,  as  is  not  unusual  with  terra-cotta  relief  work.  By 
these  means  is  obtained  what  has  long  been  a  desideratum  in 
relief  tile-work — a  compact  homogeneous  embossed  tile  of  uni- 
form quality  and  slight  shrinkage — more  surely  than  has  ever 
been  done  before. 

It  may  often  be  desirable  to  obtain  in  tile  both  the  relief  and 
intaglio  of  the  impression  in  the  clay-dust.  In  this  case  the 
relief  can  be  used  upon  the  platen  in  the  same  way  as  the  in- 
taglio. Two  of  these  tiles,  an  intaglio  and  a  relief,  may  be 
placed  face  to  face  in  the  sagger  for  firing,  and  usually  will 
separate  on  removal ;  but  it  is  best  to  insure  this  by  leaving  the 
paper  diaphragm  between  them. 

In  case  the  design  is  to  be  reproduced  smaller,  the  shrunk 
fired  tile  may  be  black-leaded  and  electrotyped. 

Of  course  these  tiles  may  have  their  intaglios  filled  with,  or 
their  reliefs  covered  with,  kiln  colors,  slip,  or  enamel,  either 
while  simply  clay  or  after  firing,  in  any  way  and  at  any  time 
proper  in  tile-making  for  such  application. 

No  good  method  of  fixing  wall-tiles  has  yet  been  contrived, 


536  BRICK,  TILES   AND   TERRA-COTTA. 

except  those  used  by  the  ancients  of  flanging  or  beveling  the 
edges  backward  and  forward  on  alternate  sides  or  in  alternating 
section  on  the  same  side,  or  in  constructing  them  with  holes 
partly  parallel  to  their  surfaces  for  cramps  or  wires  extending 
into  the  plastic  cement,  all  of  which  are  costly,  and  none  of 
which  are  adapted  for  compressed  clay- dust  work. 

Lately  on  occasions,  in  wet-clay  work,  undercut  cramp- 
grooves  have  been  made  by  hand ;  but  these  are  costly  and 
inapplicable  to  dust-work. 

Mr.  Low  employs  the  following  means  for  forming  dovetailed 
grooves  on  the  backs  of  tile :  He  cuts  one  or  more  pieces  of 
wood  of  dovetailed  cross-section  to  such  length  as  may  be  de- 
sirable, usually  long  enough  to  extend  clear  across  one  way, 
and  lays  them  on  the  platen  of  the  tile-machine  narrow  side 
down,  and  fills  in  the  clay-dust  upon  them,  or  he  places  them 
on  top  of  the  filled-in  dust,  narrow  side  up,  according  as  the 
face  of  the  tile  is  to  be  up.  or  down.  In  compression  the  nar- 
row face  of  the  wood  will  be  level  with  the  back  of  the  tile,  and 
the  clay-dust  will  mould  round  it.  In  firing,  these  formers  will 
burn  out,  leaving  their  grooves,  and  this,  if  the  wood  be  soft, 
light,  and  dry,  without  much,  if  any,  chance  of  injury  to  the  tile. 

Many  things  may  be  used  as  substitutes  for  paraffines,  such 
as  waxes,  and  compounds  of  waxes,  resins,  gums,  etc. ;  but  we 
have  not  considered  it  requisite  to  enumerate  them,  as  they 
would  clearly  be  equivalents  if  their  qualities  of  toughness, 
flexibility,  and  plasticity  resembled  those  of  paraffine. 

The  clay-dust  used  should  be  fine  enough  to  pass  a  one- 
hundred-mesh  sieve  at  largest. 

THE    MANUFACTURE    OF    WET-CLAY    FLOORING   TILES. 

The  machine  shown  in  Figs.  210  to  219  is  the  invention  of 
Mr.  George  Elberg,  of  Columbus,  O.,  and  is  for  the  manufac- 
ture of  flooring  tiles  in  connnection  with  his  process. 

He  first  prepares  a  thin  sheet  of  clay  on  paper,  which  forms 
the  finished  surface  of  the  tile- blocks.  The  second  step  con- 
sists in  the  method  of  cutting  up  the  clay  sheets  into  suitable 


ORNAMENTAL   TILES,  ETC. 


537 


sizes  to  make  the  finished  face  of  the  tile ;  and  the  third  step 
consists  in  the  method  of  combining  the  clay  sheets  with  a 
suitable  body  of  clay  to  be  pressed  and  burned  to  make  the 
finished  tile-blocks. 

Fig.  210  is  a  perspective  view  of   a  machine  for  making  the 

FIG.  210. 


veneered  tile  surface.  Fig.  21 1  is  a  central  cross-section, 
showing  the  relative  relation  of  the  rollers  shown  in  Fig.  210; 
Fig.  212,  a  side  elevation  of  a  machine  designed  for  the  second 
step  of  the  process;  Fig.  213,  a  front  elevation  of  the  same. 
Fig.  214  is  an  enlarged  side  elevation  of  the  roller-adjusting 
mechanism,  shown  in  Fig.  212  ;  Fig.  215,  a  broken  section  on 
line  x  x  of  Fig.  214;  Fig.  216,  a  perspective  view,  showing  de- 
tached parts  of  the  treadle  mechanism;  Fig.  217,  a  plan  view 
of  the  cutting-dies;  Fig.  218,  a  longitudinal  section  of  the 
cutting-dies  and  follower-board;  and  Fig.  219,  an  elevation  of 
the  rack  and  pinion. 


538 


BRICK,  TILES    AND   TERRA-COTTA. 


A  represents  the  body  or  frame  of  the  first  machine ;  A1,  the 
legs  on  which  the  parts  are  supported.     The  frame  of  the  ma- 


FlG.  212. 


FIG.  2 1 5 


chine  may  be  made  of  any  suitable  material,  and  should  be 
substantially  built. 

b  represents  a  pinion  mounted  on  a  shaft  supported  in 
journals  on  frame  A,  which  is  driven  by  a  belt  D,  running  over 
a  pulley  on  the  end  of  a  shaft  opposite  to  pinion  b.  Pinion  b 
drives  the  large  gear-wheel  B,  mounted  upon  the  axial  shaft  of 
roller  c. 

h  represents  a  pulley  on  the  same  shaft. 

/represents  a  transmitting-pulley,  mounted  on  axial  shaft  of 
roller  F.  This  axial  shaft  of  roller  F  is  journaled  upon  the 
frame  of  the  machine  in  any  suitable  manner. 


ORNAMENTAL  TILES,  ETC.  539 

H  represents  another  transmitting-pulley,  journaled  to  the 
frame  of  the  machine  on  an  independent  shaft.  Upon  the  outer 
end  of  the  shaft  is  a  transmitting-pinion,  not  shown  in  drawings, 
and  meshing  with  gear  B. 

el  represents  a  pulley  mounted  on  the  axial  shaft  of  roller  e. 
driven  by  a  belt  from  pulley  H,  as  shown  in  Fig.  210. 

The  paper  may  be  burned  off  in  the  kiln,  or  removed  after 
the  tile  has  been  completed  and  thoroughly  dried  ready  for 
burning,  leaving  an  excellent  finished  surface. 

When -delicate  colors  are  to  be  used,  it  is  preferable  to  re- 
move the  paper  before  burning ;  but  in  some  cases  the  paper 
will  burn  off  in  the  kiln  without  injury  to  the  color. 

The  thin  sheets  of  clay  formed  on  paper  we  believe  to  be  a 
new  article  of  manufacture.  The  sheets  of  clay  so  prepared 
are  united  with  an  additional  body  of  clay.  The  preferred  pro- 
cess of  carrying  out  this  part  of  the  invention  is  described  as 
the  third  step. 

The  object  of  the  machine  shown  in  Figs.  220  to  228  is  to 
press  the  tile  on  carrier-plates,  which  are  first  oiled ;  then  the 
clay  or  tile  blank  is  placed  upon  the  carrier-plates,  passed  under 
an  oil-roller,  thence  carried  between  dies  and  into  a  die  box, 
where  it  is  subjected  to  pressure  to  shape  and  form  the  tile, 
then  delivered  out  of  the  dies  by  the  automatic  and  intermittent 
action  of  the  machine  driven  by  power,  the  motion  of  the  ma- 
chine being  imparted  by  means  of  an  oscillating  shaft,  from 
which  shaft  all  parts  of  the  machine  primarily  take  their  motion 
to  successively  carry  out  the  various  steps  of  the  operation. 

Fig.  220  is  a  side  elevation  of  machine  for  oiling  the  carrier- 
plates ;  Fig.  221,  an  end  elevation  of  the  same.  Fig.  222  re- 
presents the  carrier-plate.  Fig.  223  is  a  perspective  view  of 
the  pressing-machine ;  Fig.  224,  an  end  elevation  of  the  same ; 
Fig.  225,  a  plan  view  of  the  reversing-gear ;  Fig.  226,  a  longi- 
tudinal section  on  line  x  x,  Fig.  224;  Fig.  227,  a  detailed  view 
of  one  of  the  outside  eccentrics  operating  the  die-arms ;  Fig. 
228,  a  detailed  view  of  die-arm  with  die  removed. 

A,  A\  A'2  represent  the  frame  of  apparatus  ;  a\  an  endless  car- 


540 


BRICK,  TILES    AND   TERRA-COTTA. 


rier  traveling  over  pulleys  a  a ;  a1,  carrier-blocks  secured  to 
belt  a1;  B  b,  a  ratchet  and  pawl ;  Bl,  a  belt  connecting  pulley  ft 
to  driving  pulley  B\  rigidly  secured  to  shaft  5. 


FIG.  221. 


FIG.  220. 


FIG.  222. 


FIG.  223. 


(7  is  a  roller  covered  with  sheep's  pelt  or  other  porous  sub- 
stance designed  to  hold  oil ;  c,  the  traveling  plates,  on  which  is 
placed  the  clay,  c1  are  depending  legs  or  hooks  engaging 
with  the  carrier-blocks  dl;  c*t  angle-irons,  which  act  as  ways  for 


ORNAMENTAL   TILES,  ETC. 


541 


plates  c.     The  plates  c  are  placed  upon  the  angle-irons  or  ways 
t2,  then,  by  means  of  the  carrier-blocks  a2,  are  carried  under 


FIG.  225. 


roller  C,  which  oils  the  surface.  When  they  reach  the  other 
end  of  the  machine  they  are  taken  off  by  the  operator  and 
blanks  of  clay  placed  upon  them. 


CHAPTER  XVI. 

THE    MANUFACTURE     OF     ROOFING-TILES;      THE     GLAZING    OF 

ROOFING-TILES. 

GENERAL  REMARKS. 

THE  word  tile  does  riot  often  occur  in  the  Bible ;  but  that 
tiles  were  used  in  very  ancient  times,  not  only  in  buildings,  but 
also  for  many  purposes  for  which  we  employ  paper,  there  is 
not  the  least  doubt,  and  this  is  particularly  true  in  regard  to 
Assyria,  in  which  country  almost  every  transaction  of  a  public 
or  private  character  was  first  written  upon  thin  tablets  of  clay, 
or  tiles,  and  then  baked. 

The  prophet  Ezekiel,  who  was  among  the  captives  near  the 
river  Chebar  in  the  land  of  the  Chaldeans,  is  among  the  first  to 
describe  the  use  to  which  the  tile  was  sometimes  put  for  re- 
ceiving drawings  or  portraying  of  plans. 

In  595  B.  C.  Ezekiel  was  commanded  to  make  use  of  this 
Assyrian  practice  at  the  time  when  the  siege  of  Jerusalem  was 
prefigured,  the  commandment  being  in  the  following  language  : 
"  Thou  also,  son  of  man,  take  thee  a  tile,  and  lay  it  before  thee, 
and  portray  upon  it  the  city,  even  Jerusalem."  Ezekiel  iv.  I. 

The  plan  of  the  siege  and  all  the  details  were  fully  explained, 
and  the  manner  and  period  in  which  they  were  to  be  carried 
out  were  predicted. 

From  the  profuseness  with  which  the  Assyrians  employed 
colors  in  the  decoration  of  bricks  and  many  interior  as  well  as 
exterior  architectural  positions,  and  in  their  most  gorgeously 
dyed  apparel  and  head-dresses,  household  furnishings,  horse 
equipments,  and  in  fact  every  position  that  it  was  possible  to 
attract  the  eye  or  please  the  taste,  it  is  not  improbable  that 
when  tiles  were  used  for  roofing  purposes  they  were  also  richly 

(54O 


MANUFACTURE   AND    GLAZING   OF   ROOFING-TILES.       543 

colored  and  ornamented  in  a  great  variety  of  designs,  imparting 
to  the  roofs  a  highly  ornate  appearance. 

Rome  was  originally  roofed  with  shingles,  which  gave  a  gen- 
eral invitation  to  the  great  destructive  fires  which  so  often  oc- 
curred ;  and  no  effort  seems  to  have  been  made  to  lessen  the 
danger  from  this  source  until  about  the  time  of  the  war  with 
Pyrrhus,  at  about  which  time  tiles  of  burnt  clay  were  intro- 
duced. 

In  Knight's  "  Mechanical  Dictionary"  we  find  three  good 
illustrations,  with  description  of  the  tiles  used  by  the  Greeks 
and  Romans,  and  modifications  of  the  pantile.  About  the 
time  of  Pausanias,  620  B.  C.,  tiles  of  marble  were  largely  em- 
ployed in  Greece ;  the  temple  of  Jupiter  at  Olympus,  and  of 
Athenae  at  Athens  (the  Parthenon),  were  thus  covered. 

The  ancient  Greeks  always  clung  to  marble ;  at  no  time  did 
they  show  any  great  desire  to  employ  burned  clay  in  their  ar- 
chitectural constructions.  Roof-tiles  of  bronze  and  gilt  were 
used  in  some  cases. 

The  lower  edges  of  the  joint  tiles  were  protected  and  orna- 
mented by  frontons,  and  the  edges  of  the  flat  tiles  were  turned 
up  and  covered  by  semi-cylindrical  joint  tiles,  termed  imbrices. 

FIG.  229. 


Fig.  229  shows  two  forms  of  marble  tiles,  a  being  the  form 
employed  by  the  Romans,  and  b  the  marble  tiles  sometimes 
used  by  the  Greeks  ;  and  which  have  both  been  imitated  in  clay. 

In  Roman  architecture,  both  flat  and  round  tiles  were 
largely  employed,  roofs  were  not  uncommonly  covered  with 
flat  and  curved  tiles  alternating. 


544  BRICK,  TILES    AND   TERRA-COTTA. 

The  plain  tiles  now  in  general  use  in  England  weigh  about 
from  two  to  two  and  one-half  pounds  each,  and  expose  about 
one-half  their  surface  to  the  weather,  four  hundred  of  them 
covering  one  hundred  superficial  feet  of  roof  surface ;  they  are 
sometimes  huug  upon  the  sheathing-board  by  two  oak  pins  in- 
serted through  holes  left  by  the  moulder. 

Plain  tiles  are  also  now  made  with  grooves  and  fillets  on  the 
edges,  so  that  they  can  be  laid  without  overlapping  the  usual 
distance,  the  grooves  leading  the  water.  This  may  answer  for 
some  cheap  constructions  where  lightness  is  also  a  considera- 
tion ;  but  the  plan  is  a  bad  one,  as  they  will  certainly  leak  in 
the  driving  rains  and  drifting  snows,  and  they  are  also  subject 
to  injury  by  hard  frost. 

Pantiles  were  first  used  in  Flanders,  the  wavy  surface  lapping 
under,  and  being  overlapped  by  the  adjacent  tiles.  The  Eng- 
lish pantiles  weigh  from  five  to  five  and  one-quarter  pounds, 
expose  ten  inches  to  the  surface,  and  one  hundred  and  seventy- 
five  of  them  cover  a  square,  or  one  hundred  superficial  feet  of 
roof  surface. 

A  gutter  tile  has  come  into  use  in  England ;  it  forms  the 
lower  course,  overhangs  the  lower  sheathing-board  or  lath,  and 
is  nailed  to  it. 

Sliding  tiles  are  used  as  substitutes  for  weather-boarding ; 
holes  are  made  in  them  during  moulding,  and  they  are  secured 
by  flat-headed  nails  to  the  lath. 

The  exposed  face,  called  the  gauge,  is  sometimes  indented 
to  represent  courses  of  brick ;  fine  lime  mortar  is  introduced 
between  them,  when  they  rest  one  upon  the  other. 

These  sliding  tiles  are  sometimes  called  weather-tiles,  and 
sometimes  mathematical-tiles,  the  names  being  derived  from 
their  exposure  or  marking.  They  have  a  variety  of  forms, 
having  curved  or  crenated  edges,  and  are  also  variously  orna- 
mented with  raised  or  encaustic  figures. 

Modifications  of  the  pantiles  are  shown  in  the  examples  a  b, 
Fig.  230,  the  edges  being  turned  up  and  down  respectively; 
c  d  e  are  modifications  of  the  ridge-tiles,  in  which  the  gutter 


MANUFACTURE   AND    GLAZING   OF   ROOFING-TILES.        545 

and  ridge  are  placed  alternately,  f  g  show  modes  of  securing ; 
the  first  is  moulded  with  a  lug,  which  secures  itself  in  position 
by  catching  above  the  lath  of  the  roof ;  the  second  shows  a  tile 
moulded  with  two  lugs,  by  which  it  engages  the  tiles  of  the 
courses  above  and  below. 

h,  h! ,  h"  are  elevation,  section,  and  perspective  views  of  a  tile 
exposing  a  semicircular  face  to  the  weather.  The  semicircular 
portion  has  a  drop  flange,  which  catches  over  re-entering  curves 
of  the  upper  part,  these  curves  having,  upturned  flanges  for  that 
purpose.  Whenever  roof-tiles  are  to  be  glazed,  they  are  var- 
nished after  being  burned;  the  glaze  is  then  put  on,  and  the 

FIG.  230. 


tiles  are  then  placed  in  a  potter's  oven  and  remain  until  the 
glaze  commences  to  run.  The  glaze  is  usually  made  from  what 
are  called  lead  ashes,  being  lead  melted  and  stirred  with  a  ladle 
till  it  is  reduced  to  ashes  or  dross,  which  is  then  sifted,  and  the 
refuse  ground  on  a  stone  and  re-sifted.  This  is  mixed  with 
pounded  calcined  flints. 

A  glaze  of  manganese  is  also  sometimes  employed,  which 
gives  a  smoke-brown  color. 

For  a  black  color  iron  filings  are  sometimes  used  ;  for  green, 
35 


546  BRICK,  TILES   AND   TERRA-COTTA. 

copper  slag;  and  for  blue,  smalt  is  employed,  the  tile  first 
wetted,  and  the  composition  laid  on  from  a  sieve. 

At  one  time  very  inferior  roof-riles  were  made  in  England  on 
account  of  the  careless  weathering  or  preparation  of  the  clay 
employed ;  and  in  order  to  cure  this  a  statute  of  Edward  IV. 
required  that  all  clay  for  tiles  should  be  dug,  or  cast  up,  before 
the  first  of  November,  and  not  made  into  tiles  before  the  March 
following. 

The  garden  of  the  Louvre  in  Paris  was  called  the  Tuileries, 
as  being  a  place  where  tiles  were  anciently  made ;  a  magnifi- 
cent palace  was  begun  there  in  1564  by  Catharine  de  Medicis, 
wife  of  Henry  II.,  finished  by  Henry  IV.,  and  splendidly 
adorned  by  Louis  XIV.,  but  was  sadly  defaced  in  our  times, 
during  the  Commune  of  1871. 

Modern  tile-covered  roofs  add  greatly  to  the  picturesque  ap- 
pearance of  buildings. 

A  portion  of  a  roof  covered  with  diamond  shaped  tiles  is 
shown  in  Fig.  231,  and  the  form  of  the  tile  is  shown  in  a  sec- 
tion, and  a  plan  of  face  and  bed. 

Fig.  232  shows  a  roof  covered  with  tiles  of  various  shapes, 
and  Fig.  233  shows  the  six  forms  of  roofing  tiles  in  most  com- 
mon use  in  this  country. 

A  great  advantage  for  the  tile  roof  is  that  it  is  a  non-conduc- 
tor, and,  therefore,  cooler  in  the  summer  season  than  any  other 
kind  of  roof.  The  buff  tile,  being  lighter  in  color,  is  the  cool- 
est, as  it  does  not  absorb  the  rays  of  the  sun.  Tiles  are  also  a 
better  protection  against  lightning  than  the  lightning-rod,  as 
the  latter  attracts  electricity,  while  the  former  is  a  non-conduc- 
tor. Insulators,  made  of  pottery,  are  extensively  used  on  tele- 
graph lines  in  Europe  and  portions  of  America. 

The  rain-water  collected  from  a  tile  roof  is  much  purer  and 
cleaner  than  from  any  other  kind  of  roof,  as  the  tiles  are  very 
smooth,  and  no  dust  or  soot  settles  upon  them. 

Tiles  are  indestructible,  and  are  not  affected  by  heat  or  cold. 
They  will  not  crack  and  slide  off  the  roof,  like  slate,  leaving  the 
sheathing  exposed,  when  subjected  to  sudden  heat,  as  by  the 
burning  of  an  adjoining  building. 


MANUFACTURE   AND    GLAZING   OF   ROOFING-TILES.       547 
FIG.  231.  FIG.  233. 


FIG.  232. 


After  doing  service  on  one  structure,  the  tile  can  be  taken  off 
and  used  on  other  buildings.  Tiles  should  not  be  put  upon  a 
roof  that  has  less  than  one-quarter  pitch  (a  slant  of  six  inches 


548  BRICK,  TILES   AND   TERRA-COTTA. 

to  the  foot),  although  we  have  seen  some  roofs  of  less  pitch 
which  were  satisfactory.  A  roof  to  support  tile  should  be  some- 
what stronger  than  for  shingles.  The  rafters  should  be  2x6,  1 8 
inches  apart,  and  well-stayed,  so  that  they  cannot  spread.  The 
sheathing  should  be  of  soft  wood,  of  even  thickness,  and  close 
together.  Generally  felt  or  tarred  paper  is  placed  under  the 
tile,  although  it  is  not  necessary  to  make  the  roof  water-tight, 
but  it  stops  circulation,  and  makes  the  roof  warmer  in  winter, 
and  adds  but  little  to  the  cost. 

THE   PROCESS   OF    MANUFACTURING   ROOFING-TILES. 

When  the  process  of  manufacturing  roofing-tiles  is  conducted 
'by  hand,  the  method  is  nearly  the  same  in  this  country  as  in 
England,  and  but  few  improvements  have  been  made  in  this 
mode  of  production ;  but  by  the  machine  process  we  are  en- 
abled to  manufacture  very  satisfactory  roofing-tiles  at  but  a 
small  cost. 

The  clay  of  which  the  tiles  are  made  is  dug  and  spread  out  in 
shallow  beds  to  disintegrate,  and  a  hot  sun  or  dry  frosty  weather 
is  best  for  this. 

In  all  cases  the  clay  should  next  be  finely  pulverized  by  pass- 
ing through  iron  rollers  or  other  suitable  appliances,  and  too 
much  care  cannot  be  given  to  this  branch  of  the  preparation  of 
the  clay,  as  has  before  been  observed. 

A  good  pug-mill  is  one  which  can  have  the  knives  made 
larger  at  the  top  than  at  the  bottom  and  used  for  tempering 
the  clay  when  the  tiles  are  made  by  hand. 

The  usual  form  of  pug-mill  employed  in  England  is  generally 
six  feet  high,  three  feet  in  diameter  at  the  larger  or  upper  part, 
and  two  feet  at  the  bottom. 

The  clay  is  kneaded  and  completely  mixed  by  a  revolving 
cast-iron  spindle,  which  carries  a  series  of  flat  steel  arms,  so  ar- 
ranged as  to  form  by  rotation  a  worm-like  motion  upon  the  clay, 
which  is  pressed  from  the  larger  to  the  smaller  diameter  of  the 
tub  in  which  the  clay  is  confined,  and  finally  comes  oozing  out 
of  an  aperture  in  the  bottom.  In  this  manner  of  tempering 
great  cohesive  power  is  given  to  the  clay. 


MANUFACTURE   AND    GLAZING   OF   ROOFING-TILES.        549 

The  clay  is  then  ready  to  make  roofing-tiles ;  the  moulding  is 
usually  conducted  in  a  shed,  and  most  of  the  manufacturers 
prefer  to  place  their  tiles  in  the  open  air,  if  the  weather  allows. 

The  moulding  table  or  bench  is  supported  on  four  legs,  which 
are  well  under  the  table,  leaving  the  two  ends  of  the  top  of  the 
table  to  project  liberally.  The  coal-dust  box,  14x8  inches,  is  at 
the  left  hand  of  the  moulder,  at  the  corner  of  the  table,  and  the 
moulding-board,  14x10  inches,  is  usually  placed  slightly  to  the 
right  of  the  coal-dust  box. 

The  mould  employed  is  12x7^  inches  and  y2  inch  thick, 
made  of  oak,  and  usually  plated  with  iron. 

The  moulder  works  a  lump  of  clay  by  hand  into  an  oblong 
square,  the  mould  is  placed  on  the  bench,  and  fine  coal-dust 
sprinkled  over  it ;  the  lump  of  clay  is  then  taken  up  and  thrown 
into  it  with  force,  which  is  cut  off  level  with  the  top  of  the 
mould  by  a  brass  wire,  strained  upon>a  wooden  bow;  the  lump 
of  surplus  clay  is  removed,  and  that  in  the  mould  is  finished  by 
adding  a  little  clay  to  it,  if  necessary,  and  smoothing  the  face 
over  with  a  wooden  tool. 

The  moulded  tile  is  then  placed  upon  a  thin  board,  first 
sprinkled  with  fine  coal-dust,  and  so  the  process  is  repeated, 
the  lump  of  clay  being  added  to  every  time  six  tiles  that  are 
moulded.  The  off-bearer  carries  two  tiles  at  a  time,  one  on  his 
head  and  one  on  his  hands,  to  the  floor,  where  they  are. al- 
lowed to  remain  for  four  hours  out  of  doors  in  fair  weather,  and 
then  collected  and  placed  together,  the  nib  end  changed  alter- 
nately, so  as  to  hack  them  closely  and  squarely. 

In  this  condition  they  remain  for  two  days,  so  as  to  allow 
them  to  toughen ;  the  situation  of  this  hacking  should  be  dry, 
but  not  hot. 

The  set  or  curved  form  is  then  given  by  placing  six  of  the 
tiles  at  one  time  on  the  top  of  the  horse,  which  is  a  three-legged 
stool,  having  the  top  about  three-quarters  of  an  inch  longer 
than  the  tile,  the  top  being  a  convex  curve  to  a  radius  of  about 
10  feet  and  3  inches,  and  having  a  height  of  about  2  feet  7 
inches  from  the  level  of  the  ground  to  the  top  of  the  block. 


550  BRICK,  TILES   AND   TERRA-COTTA. 

The  nib  end  is  reversed  each  time  so  as  to  allow  the  tiles  to 
lie  closely  together  without  injury,  and  a  wooden  block  lifted 
on  top  of  the  tiles,  raised  by  the  projecting  ends,  and  three 
quick  blows  given  with  it  on  the  tiles ;  this  block  is  concave 
and  curved,  so  as  to  correspond  with  and  fit  neatly  over  the 
upper  surface  of  the  horse. 

The  tiles  are  then  carried  away  and  stacked  edge  together  in 
the  shape  of  a  half  diamond,  three  tiles  being  used  to  form 
each  side ;  two  laths  are  then  placed  on  the  top  of  the  first 
hack  of  tiles,  one  lath  at  each  outer  edge ;  another  hack  of  tiles 
is  placed  on  the  laths,  so  arranged  as  to  form  a  full  diamond 
with  the  openings  left  between  the  first  course  of  tiles ;  two 
laths  are  then  placed  in  the  same  way  on  the  top  of  the  second 
course  of  tiles,  and  the  third  course  is  then  hacked  so  as  to  form 
a  full  diamond,  with  the  openings  left  between  the  second 
course  of  tiles. 

This  is  the  final  drying,  and  they  are  then  carried  to  the 
oven  twelve  at  a  time,  with  the  edges  of  the  tiles  resting  against 
the  breast  of  the  carrier. 

Objections  to  roofing  tile,  in  this  country,  have  heretofore 
been  made  to  the  effect  that  the  tile  was  heavy,  made  of  coarse 
clay,  poorly  burned,  that  it  would  absorb  a  great  amount  of 
moisture,  so  that  freezing  and  thawing  would  cause  it  to 
crumble,  and,  in  appearance,  it  was  anything  but  handsome. 
Whatever  foundation  these  objections  may  have  had  in  the  first 
product  of  tiles,  our  manufacturers  have  now  fully  met  and 
remedied  these  drawbacks  to  their  use. 

All  roof-tiles  require  more  careful  burning  than  brick,  and 
before  they  are  placed  in  the  oven,  the  bottom  is  covered  with 
brick,  so  as  to  take  the  first  flash  of  the  fire,  which  would  de- 
stroy a  course  of  tiles  in  that  position  from  the  warping  and 
discoloring. 

On  the  top  of  this  course  of  brick  about  nine  thousand  tiles 
are  set,  which  form  a  square  in  the  heart  of  the  kiln,  the  space 
between  the  tiles  and  the  curved  sides  of  the  oven  being  usually 
filled  with  brick. 


MANUFACTURE   AND    GLAZING   OF    ROOFING-TILES.        551 

The  tiles  are  set  edgewise  in  lots  of  twelve,  called  bungs, 
changing  their  direction  with  each  lot,  being  set  cross  and 
lengthwise  alternately.  They  are  placed  in  a  vertical  position, 
and  the  nibs  of  the  tiles  space  them  off  from  each  other  and 
support  them  in  a  vertical  position ;  the  checkered  manner  in 
which  they  are  placed  in  the  oven  insuring  full  action  of  the 
fire  through  the  stock. 

A  uniformity  of  heat  is  a  great  desideratum  in  burning  tiles, 
and  the  old  form  of  circular  oven,  so  much  employed  in  Staf- 
fordshire, is  found  to  answer  the  purpose,  and  do  the  work 
more  thoroughly  than  any  other  in  use. 

A  wall  is  sometimes  built  around  the  oven  in  order  to  pro- 
tect the  fires,  and  prevent  one  from  being  urged  more  than 
another  by  the  changing  direction  of  the  wind. 

A  sufficient  space  is  left  between  the  wall  and  the  oven  to 
allow  the  fireman  to  attend  conveniently  to  his  fires ;  five  feet 
six  inches  usually  being  high  enough  for  this  wall. 

The  oven  having  been  filled,  the  doorway  is  walled  up  with 
brick  and  faithfully  daubed  over  with  loam  and  sand,  the  fires 
are  lighted  and  kept  slowly  burning  for  the  first  five  hours, 
after  which  time  they  are  then  progressively  increased  for  the 
next  thirty-three  hours,  making  the  total  time  thirty-eight 
hours  for  hard-fired  tiles,  four  tons  of  coal  being  consumed  in 
the  burning.  The  fireman  determines  the  heat  by  directing  his 
sight  to  the  mouths  and  top  outlet  of  the  oven ;  when  the  heat 
is  reached,  and  before  the  fires  burn  hollow,  the  mouths  are 
stopped  up  with  ashes  to  prevent  the  cold  air  from  cooling  the 
oven  too  quickly. 

The  ovens  are  fired  once  a  week,  but  can  be  fired  easily  three 
times  in  two  weeks  if  so  desired. 

The  manufacture  of  plain  roofing-tiles  can  be  conducted  with 
a  small  capital,  the  process  and  requirements  not  being  very  in- 
tricate or  expensive. 

But  to  conduct  the  manufacture  of  all  the  tiles  required  for 
roofing,  and  the  other  articles  generally  produced  in  large 
tileries,  requires  a  large  capital  and  a  thorough  knowledge  of  the 
business  in  all  its  details. 

^*SCPTHE 

"UNIVERSITY 

Of 


552  .  BRICK,  TILES   AND   TERRA-COTTA. 

In  all  the  large  tile-works,  all  the  operations  of  manufacture 
are  conducted  under  shelter,  and  a  great  variety  of  articles  are 
produced,  of  which  the  following  list  is  but  a  part:  — 

Chimney-pots,  circulars  for  setting  furnaces,  etc.,  column- 
brick  for  forming  columns,  drain-pipes,  drain-tiles,  fire-brick, 
garden-pots,  hip-tiles,  oven-tiles,  paving-tiles,  pantiles,  plain- 
tiles,  ridge-tiles,  and  anything  in  the  line  required  to  order. 

With  the  exception  of  fire-brick,  the  clay  used  for  all  these 
articles  is  the  same ;  but  for  circular-brick,  column-brick,  kiln- 
brick,  oven-tiles,  paving-tiles,  and  paving-brick  a  certain  quan- 
tity of  loam  is  mixed  with  it,  which  for  oven-tiles  must  be  of  a 
very  good  character. 

To  faithfully  describe  the  manufacture  of  these  various  articles 
would  increase  the  size  of  this  chapter  out  of  all  proportion  to 
its  design.  The  principle  of  procedure  is  the  same  in  eachcase, 
but  no  two  articles  are  made  or  finished  in  a  similar  way,  each 
requiring  different  tools  and  moulds. 

The  London  tileries,  which  are  the  largest  in  the  world,  pay 
particular  attention  to  proper  preparation  of  the  clay  for  the 
particular  purpose  for  which  it  is  to  be  used ;  there  not  being 
the  same  haste  to  get  the  clay  into  the  kiln  that  is  shown  in 
some  smaller  manufactories. 

The  first  stage  in  London  tileries  is  the  weathering,  which  is 
about  the  same  as  has  been  described  for  plain  tiles,  the  object 
being  to  open  the  pores  of  the  clay,  separate  the  particles,  and 
thereby  compel  it  to  absorb  the  water  more  readily  in  the  pro- 
cess of  mellowing. 

This  is  accomplished  by  throwing  the  clay  into  pits,  covering 
with  water  and  leaving  it  to  soften  or  ripen.  The  clay  is  now 
usually  passed  through  the  rollers  and  the  stones  taken  out 
before  it  is  put  into  soak,  which  is  a  term  also  used  for  the 
mellowing  process. 

The  kilns  used  for  burning  the  wares  produced  are  usually 
conical  in  shape  for  more  than  one-half  the  height,  about  40 
feet  wide  at  the  base,  and  having  a  total  height  of  about  25  feet 
from  the  bottom  of  the  ash-pit  to  the  top  of  the  dome,  which  is 


MANUFACTURE   AND   GLAZING   OF   ROOFING-TILES.        553 

slightly  convex.  These  kilns  arc  quite  expensive  to  build, 
eight  thousand  dollars  being  about  a  fair  average ;  fire-brick 
being  generously  employed  in  the  interior.  This  class  of  kilns 
is  largely  used  for  burning  pantiles. 

Before  the  pantiles  are  placed  in  the  kiln,  one  course  of  burned 
brick  is  laid,  herring-bone  fashion,  one  and  one-half  inch  apart 
over  the  bottom. 

The  tiles  are  then  stacked  upon  this  as  closely  as  they  can  be, 
one  course- above  the  other.  The  hatchways  are  bricked  up  as 
the  body  of  the  kiln  is  filled.  When  the  top  layer  is  done,  it  is 
covered  or  platted  with  one  course  of  unburned  tiles  laid  flat; 
then  on  the  top  of  these  a  course  of  burned  pantiles  is  loosely 
laid.  The  hatchways  are  carefully  daubed  over,  the  fires  lighted 
and  kept  gently  burning  for  twenty-four  hours,  and  then  grad- 
ually increased,  until  at  the  end  of  six  days  they  are  left  to  die 
out,  the  burning  being  accomplished^ 

The  class  of  goods  which  the  kiln  contains  has  a  great  influ- 
ence upon  the  quantity  of  fuel  consumed  in  a  burning,  chim- 
ney-pots, garden-pots,  etc.,  not  requiring  so  much  as  more 
solid  goods. 

In  this  country,  the  manufacture  of  roofing-tiles  is  a  compar- 
atively new  industry ;  but  it  is  rapidly  growing  in  public  favor, 
and  their  employment  is  becoming  quite  general. 

Many  large  and  costly,  as  well  as  small  or  ordinary  dwelling- 
houses,  church  buildings,  extensive  work-shops,  barns,  etc.,  are 
covered  with  tile  roofs. 

With  us,  the  tiles  are  usually  of  three  colors,  red,  bufif,  and 
black.  The  color  of  the  red  tile  is  produced  by  the  employ- 
ment of  clay  containing  a  large  per  cent,  of  oxide  of  iron ;  this 
is  sometimes  present  in  the  beds  with  fire-clays,  which  are  the 
class  usually  employed  for  roofing-tiles;  at  other  times,  it  is 
necessary  to  mix  some  foreign  clay,  containing  a  large  per  cent, 
of  oxide  of  iron,  with  the  material. 

The  color  is  made  deeper  and  more  uniform  by  rubbing  the 
tiles  with  finely-sifted  red  moulding  sand ;  this  should  be  done 
while  the  tile  is  quite  damp,  so  as  to  get  the  sand  to  stick  or 
hold  to  the  faces. 


554  BRICK,  TILES   AND   TERRA-COTTA. 

The  buff-colored  tile  is  made  of  nearly  pure  fire-clay,  and  it 
is  slightly  lighter  in  weight  than  the  red  tile. 

The  black  tile  is  made  by  washing  it  over  before  burning 
with  manganese  dissolved  in  water,  which,  in  the  process  of 
burning,  is  converted  into  a  perfectly  durable  coating  of  great 
hardness. 

The  patterns  usually  employed  with  us  for  roofing-tiles  are 
of  several  kinds  ;  the  large  diamond,  the  small  diamond  shingle, 
round  corner,  round  end,  gothic,  etc. 

The  large  diamond  tiles  are  14  inches,  the  length  of  the  dia- 
mond, and  8^  inches  in  the  width ;  250  cover  one  hundred 
surface  feet,  10  by  10  feet,  called  a  "  square,"  and  weigh  650 
pounds. 

They  are  fastened  with  two  sixpenny  galvanized  iron  or 
tinned  nails.  This  kind  of  tile  is  used  more  than  the  other 
styles,  as  it  is  lighter  in  weight,  and  less  in  cost. 

The  small  diamond,  6  by  10  inches,  requires  500  to  cover  a 
square,  and  it  weighs  600  pounds.  It  is  nailed  with  five-penny 
nails,  and  is  used  more  especially  for  towers,  porches,  dormer 
windows,  and  in  side  panels,  for  ornamental  purposes. 

The  shingle  tiles  are  the  plain,  flat  tiles  described  in  the  com- 
mencement of  this  chapter ;  they  are  three-eighths  of  an  inch 
thick,  have  two  counter-sunk  nail-holes,  and  are  made  of  any 
size,  not  exceeding  6  by  12  inches;  they  can  be  had  for  round 
or  square  towers,  dormer  windows,  etc.,  and  the  points  are 
sometimes  cut  semicircular,  octagonal,  gothic,  or  pointed. 

They  have  been  largely  used  in  the  Eastern  States,  and  on 
some  expensive  buildings  for  roofing  and  side  ornamentation, 
as  at  the  State  capitol  at  Albany,  New  York,  on  which  building 
they  are  wired  to  iron  ribs. 

These  tiles  are  generally  laid  about  5  inches  exposed  to  the 
weather,  which  requires  about  480  for  a  square,  weight  being 
1 100  pounds. 

The  pantiles  measure  12  inches  in  length  by  6^/2  inches  in 
width  at  one  end,  and  4^  at  the  other,  and  if  they  are  lapped  3  J^ 
inches  on  the  roof,  350  will  be  required  for  a  square,  which  will 
weigh  850  pounds. 


MANUFACTURE   AND    GLAZING    OF    ROOFING-TILES.        555 

This  kind  of  tile  makes  a  strong  roof  cover,  and  can  be 
walked  upon  without  danger  of  breaking,  and  is  especially  suit- 
able for  workshops  and  factories  ;  it  is  sometimes  made  with  lugs 
to  hang  on  to  ribs,  the  use  of  nails  being  therefore  avoided, 
which  are  liable  to  rust  away  where  much  bituminous  coal  is 
used.  It  is  also  made  with  nail-holes  to  secure  it  to  the  sheath- 
ing. Brick-making  is  now  mostly  done  by  machinery,  and 
there  is  not  the  least  doubt  but  that  tiles  of  all  kinds  will  also  be 
generally  so  made  both  in  this  country  and  in  Europe. 

The  roofing-tiles  which  have  just  been  described  are  made  by 
machinery  by  the  firm  of  J.  C.  Ewart  &  Co  ,  Akron,  Ohio. 

The  machines  which  they  employ  were  patented  by  Mr.  C.  J. 
Merrill  about  twenty-five  years  ago. 

Roofing-tiles  are  now  often  made  by  running  the  clay  through 
a  stiff-clay  machine,  the  blanks  being  formed  thereby,  and  then 
pressing  the  blanks  upon  a  hand  br  power  press  such  as  is 
made  by  C.  W.  Raymond  &  Co.,  of  Dayton,  Ohio. 

BURNED    CLAY    AS   ROOFING    MATERIAL.* 

Under  the  head  of  burned  clay  as  a  roofing  material,  the 
word  tile  expresses  the  material  it  is  made  of,  how  it  is  made, 
and  its  uses.  "The  Century  Dictionary"  defines  the  word  tile  as 
a  thin  slab  of  baked  clay  used  for  covering  the  roofs  of  build- 
ings, etc.  A  thin  slab  of  tin,  iron,  or  metal  of  any  kind  is  not 
tile.  Tile  is  burned  clay  as  a  roofing  material,  and  nothing 
else,  and  that  is  what  I  want  to  occupy  your  attention  with  for 
a  few  minutes. 

Edward  L.  Morse  published  a  series  of  articles  in  the  Ameri- 
can Architect,  in  1892,  on  the  older  form  of  roofing  tiles,  that 
are  exhaustive  in  tracing  their  history.  He  traces  their  use 
back  to  China,  several  thousand  years  before  Christ,  and  says 
they  were  made  even  before  the  sloping  roof  was  first  used. 
Palm  leaves,  straw,  and  the  bark  of  trees  formed  the  first  cover- 

*  From  a  paper  read  before  the  National  Bookmakers'  Association  at  Louisville, 
Ky.,  January  26,  1893,  by  John  R.  Elder,  President  of  Clay  Shingle  Co.,  Indianapolis, 
Ind. 


556  BRICK,  TILES   AND   TERRA-COTTA. 

ings  for  sloping  roofs,  and  then  came  terre-cotta  tile,  made  in 
the  form  of  bark,  with  the  larger  pieces  curving  upward,  and 
smaller  pieces  to  cover  the  joints.  Relics  of  these  ancient  tiles 
are  found  in  the  art  galleries  in  Berlin,  Dresden  and  London. 
The  articles  are  illustrated  with  cuts  of  tiles  made  in  different 
countries,  and  it  is  a  remarkable  fact  that  tile  are  made  and 
used  in  this  country  to-day  of  the  same  general  form  that  was 
used  four  thousand  years  ago. 

In  his  classification,  Mr.  Morse  shows  that  the  Normal 
(Asiatic)  tile  were  used  in  the  Orient,  Ancient  Greece  and 
Italy,  China,  India,  Greece  and  Italy,  the  Pan  (Belgic),  in 
England,  Scandinavia,  Belgium,  Holland,  Japan,  Java  and 
various  modern  countries;  the  Flat  (Germanic),  in  Germany, 
Austria,  Hungary,  Poland,  Switzerland,  France  and  England. 

In  the  shape  and  form  of  these  tiles  you  will  see  the  same 
shapes  and  forms  most  generally  used  to-day,  both  in  Europe 
and  America.  It  is  shown  that  these  old  forms  of  tile  are 
bedded  in  mud  and  clay — it  is  necessary  in  laying  most  of  the 
tiles  made  at  this  day  to  bed  them  in  cement.  The  most  ar- 
tistic tiles  are  found  in  China,  Korea  and  Japan,  where  they  are 
highly  glazed,  in  different  colors,  with  very  elaborate  finishings, 
making  a  very  showy  and  ornamental  roof. 

The  old  form  of  tile  were  made  of  material  the  most  endur- 
ing of  man's  fabrications,  and  the  terra-cotta  roof  tile,  when 
properly  made,  is,  all  things  considered,  one  of  the  cheapest  and 
most  durable.  Acting  as  a  non-conductor,  the  upper  portion 
of  the  house,  under  a  tile  roof,  is  warmer  in  winter  and  cooler 
in  summer.  Slate  absorbs  and  transmits  a  great  deal  of  heat. 
Shingles  are  shortlived,  and  a  menace  in  times  of  conflagration. 
With  the  best  tile  clays  in  the  world,  and  an  abundance  of  the 
unskilled  labor  usually  employed  in  making  tile,  there  is  no 
reason  why  roofing  tile  should  not  come  into  common  use  in 
this  country,  as  they  have  in  all  other  parts  of  the  world.  These 
are  the  conclusions  of  Mr.  Morse,  and  after  an  exhaustive  inves- 
tigation of  tile  roofing  I  must  say  that  I  fully  agree  with  him. 

In  "  the  Encyclopedia  of  Architecture  and  Construction,"  A. 


MANUFACTURE   AND    GLAZING   OF   ROOFING  TILES.       557 

Rospide  has  an  article  on  roofing  tile  in  France,  which  gives  a 
good  description  of  the  latest  improvements.  He  divides  his 
article  on  Roofing  Material  into  four  parts:  first,  Clay;  sec- 
ond, Stone;  third,  Metallic;  and  fourth,  Wood — giving  the 
preference  in  the  order  named.  In  speaking  of  the  manufac- 
ture of  tile,  he  says  it  is  still  carried  on  just  as  it  was  before  the 
development  of  machinery.  The  clay  must  be  selected  with 
great  care,  reduced  to  a  paste,  run  into  a  plaster  mould,  then 
dried  and  burned.  This  necessarily  makes  the  tile  thick,  and 
requires  a  great  deal  of  trimming  and  handling.  The  simple 
and  flat  tile  was  long  ago  almost  universally  superseded  by  the 
lapping  and  interlocking  tile.  He  says  the  following  are  requi- 
sites of  every  good  roofing  material : 

1st.  It  must  exclude  moisture,  which  rots  wooden  frame- 
work. 

2d.  It  must  be  capable  of  withstanding  the  forces  of  the 
wind,  and  must  admit  of  provision  for  all  expansion  and  con- 
traction consequent  upon  variations  in  temperature. 

3d.  It  must  not  overweight  the  trussing  so  as  to  increase  the 
size  of  the  supporting  timbers. 

4th.  It  must  be  fire-proof. 

5th.  The  original  expense  should  be  consistent  with  the  pur- 
pose which  the  construction  is  to  serve. 

6th.   It  should  require  but  little  care. 

Every  one  of  these  conditions  is  fully  complied  with  by  the 
tile  made  under  the  patents  of  the  Clay  Shingle  Company. 

Louis  H.  Gibson,  architect,  spent  years  in  France  and  Ger- 
many, investigating  their  manner  of  building,  especially  in  con- 
structing their  houses  so  as  to  be  secure  from  fires.  He  speaks 
in  no  uncertain  way  about  burnt  clay  for  covering  houses.  It 
is  the  ideal  covering — the  only  material  that  is  reliable,  and  will 
stand  the  test  for  centuries.  He  says: 

"  The  arguments  in  favor  of  a  tile  roof  are  too  old  and  too 
numerous  to  need  anything  more  than  mere  mention.  If  we 
stop  to  think  about  it,  we  know  that  the  roofing  material  in 
general  use  is  far  from  satisfactory.  Slate,  at  best,  is  a  tempo- 


558  BRICK,  TILES   AND   TERRA-COTTA. 

rary  roofing;  it  is  readily  affected  by  heat;  so  much  so,  indeed, 
that  a  little  heat  will  expose  all  of  the  wood  work  of  an  ordi- 
nary roof  to  the  action  of  fire.  Shingles  are  as  inflammable  as 
it  is  possible  to  arrange  the  same  amount  of  wood.  Slate  and 
shingles,  as  we  know,  are  the  general  roofing  materials.  Tiles, 
being  a  clay  product,  afford  protection  to  all  wood  work  under 
them,  in  a  perfectly  satisfactory  way.  The  heat  does  not  affect 
the  tiles  in  the  least.  Frost  affects  them  much  less  than  slate. 
The  covering  of  a  roof  with  tile  practically  means  not  only 
protection  from  the  elements,  but,  as  well,  protection  from  con- 
flagrations, or  any  unusual  or  dangerous  degree  of  heat.  Heat, 
as  we  know,  cannot  affect  burnt  clay  products.  This  quality, 
together  with  its  abilty  to  resist  other  elements  of  nature,  ren- 
ders it  the  ideal  building  material.  Its  qualities  of  this  charac- 
ter are  quite  as  apparent  for  roof  covering  as  for  other  uses. 
For  some  reason,  not  easily  understood,  tile  roofs  have  not 
been  generally  manufactured  in  America.  While  the  field  is 
open,  and  while  there  is  a  general  demand  for  the  material,  it  is 
not  satisfied.  There  is  a  difficulty  in  securing  a  satisfactory 
tile  roof  at  a  moderate  price. 

"  For  the  purpose  of  demonstrating  the  real  value  of  tile  roofs, 
I  choose  to  go  back  to  their  history  in  France.  There  are  many 
roofs  existing  in  this  country  which  are  not  quite  one  thousand 
years  old,  and  those  of  the  tenth  and  eleventh  centuries  are 
common  indeed.  What  better  evidence  of  their  quality  can  be 
asked?" 

In  the  western  part  of  Indiana,  in  a  small  country  town,  lives 
a  very  intelligent  old  gentleman.  He  is  a  carpenter,  and  sup- 
ports himself  and  family  by  work  at  his  trade.  He  had  traveled 
very  little,  his  business  did  not  allow  him  much  time  for  reading, 
but  he  was  a  great  thinker.  He  had  an  inventive  mind,  and 
understood  the  use  of  tools.  As  there  were  excellent  clays  in 
his  town,  he  tried  to  form  a  tile  for  roofing  houses.  He  spent 
all  his  spare  time  and  money  for  years  in  experimenting.  The 
forms  he  made  were  burned  in  a  fire-brick  factory  near  by.  When 
he  had  got  a  good  point  he  kept  it,  and  changed,  and  altered, 


MANUFACTURE   AND    GLAZING    OF   ROOFING   TILES.       559 

and  improved  until  he  succeeded  in  getting  what  he  believed 
to  be  just  the  thing.  He  wanted  a  tile  that  would  be  strong, 
light  on  the  roof,  that  would  be  guarded  at  every  point  against 
sleet,  rain  and  drifting  snow ;  that  would  be  wind,  water  and 
frost  proof,  and  fire  proof ;  that  could  be  made  by  machinery 
at  a  small  expense,  and  could  be  worked  and  burned  without 
loss.  After  getting  all  these  points  to  his  satisfaction,  he  con- 
sulted a  patent  attorney  and  found  his  form  and  principle  was 
new — that  his  title  was  patentable.  He  secured  one  patent, 
and  followed  that  with  others,  until  he  now  has  six.  Like  most 
inventors,  he  had  no  money  to  manufacture  his  tile.  He  had 
neither  money  nor  influence  to  seek  the  capital  necessary. 
After  several  years  the  president  of  the  railroad  running  through 
his  town  became  interested  in  his  invention,  and  through  his 
influence  the  necessary  capital  was  obtained.  A  factory  was 
started.  Again,  time  and  money  were  spent  in  putting  his  theo- 
ries into  practical  use.  Tile  were  made — the  factory  was  run 
successfully  and  profitably,  and  to-day  some  splendid  buildings 
are  covered  with  tile  made  at  his  little  factory.  He  can  show 
roofs  equal  to  any  in  the  world.  Unfortunately,  the  factory 
burned,  and  has  not  yet  been  rebuilt,  but  four  factories  are  now 
at  work  in  different  parts  of  the  country,  and  before  this  year 
is  out  more  tile  will  be  made  of  his  pattern,  and  under  his 
patents,  than  in  all  the  other  tile  factories  in  the  United  States. 
Architects  and  others  often  wonder  why  more  tile  have  not 
been  used  in  the  United  States.  This  question  is  easily  an- 
swered. In  the  first  place  this  was  a  timber  country,  clap- 
boards and  shingles  were  easily  made  out  of  timber,  and  they 
formed  a  cheap  roof  that  answered  the  purpose  for  a  time. 
Then  came  slate,  and  tin,  and  galvanized  iron,  and  felt,  and 
gravel,  that  could  always  be  obtained  when  wanted,  were  light 
and  cheap.  Tile,  as  made,  were  heavy,  expensive,  hard  to  get, 
and  in  consequence  were  only  used  on  expensive  buildings, 
that  could  contract  for  them  in  ample  time.  Many  have  tried 
to  make  tile,  but  the  rule  has  been  to  follow  the  old  forms  of 
tile,  and  the  old  manner  of  making  them,  so  that  there  was  no 


560  BRICK,  TILES    AND   TERRA-COTTA. 

profit  in  it.  Both  Mr.  Morse  and  Mr.  Rospide,  quoted  above, 
confirm  this  fact.  The  manufacture  of  tile  has  not  kept  pace 
in  advancement  with  that  of  any  other  branch  of  clay  industry. 
The  idea  has  been  to  invent  a  machine  to  make  tile  easily  and 
cheaply,  while  the  fact  is,  there  is  plenty  of  machinery  exactly 
suited  for  the  purpose.  The  brick  presses  of  to-day  can  make 
tile  just  as  easily  as  they  can  make  brick,  and  the  best  of  these 
are  not  expensive.  I  would  not  consider  a  re-press  expensive 
that  will  make  4,000  tile  a  day,  and  cost  but  $225.00.  The 
German  press  that  forms  the  tile  in  plaster  moulds  is  not  what 
progressive  Americans  want.  The  application  of  our  improved 
machinery  in  preparing  clay,  and  forming  tile,  is  a  long  step  in 
the  direction  of  increasing  the  use  of  tile,  improving  their  qual- 
ity and  cheapening  their  cost. 

So  far  as  I  have  been  able  to  learn,  there  are  only  five  tile 
works  in  the  United  States.  Three  of  these  are  in  Baltimore 
and  two  in  Ohio.  Terracotta  works  have  made  tiles  on  or- 
ders, but  it  is  a  branch  they  have  not  prepared  for,  and  they 
only  make  them  when  they  feel  compelled  to.  There  are  more 
tile  made  by  one  factory  in  Ohio  than  by  all  the  balance  in  the 
United  States.  This  fact  would  indicate  that  making  roofing- 
tile  has  not  been  profitable  in  this  country,  and  this  is  prob- 
ably true,  as  we  find  where  any  business  is  successful  competi- 
tion starts  up  all  around  it.  In  our  opinion  the  reason  the  tile 
business  has  not  been  more  successful  is  because  the  old  form 
of  tile,  and  the  way  of  making  them  in  the  old  country,  has 
been  followed  in  this.  The  tile  is  too  heavy,  has  to  be  laid  in 
cement,  and  the  improved  machinery  has  not  been  used  in 
making  them.  And  again,  stocks  have  never  been  kept  on 
hand  to  fill  orders  on  short  notice.  When  you  think  of  the 
vast  sums  that  are  spent  each  year  in  buildings,  and  that  fully 
one-twentieth  of  the  cost  of  all  these  buildings  is  for  the  roofs, 
you  can  see  what  a  business  can  be  done,  if  the  tile  can  be  had 
at  a  reasonable  price. 

In  speaking  of  the  tile  factories  above,  I  did  not  include  four 
that  have  been  started  within  the  last  year  to  make  tile  under 


MANUFACTURE   AND   GLAZING   OF   ROOFING  TILES.       §6 1 

the  patent*  of  the  Clay  Shingle  Company.  One  factory  has 
been  started  at  Baltimore,  one  at  Trenton,  N.  J.,  one  at  Chi- 
cago, and  one  at  Denver.  Before  this  yeaf  is  out  all  these  fac- 
tories will  be  making  tile  on  a  large  scale,  and  negotiations  are 
now  pending  for  several  other  factories. 

In  considering  the  value  of  roofing-tile  the  question  of  pro- 
tection from  fire,  and  insurance,  enters  largely  into  the  account. 
In  these  days  when  so  much  money  is  spent  in  fire-proofing 
the  insides  of  buildings  with  hollow  brick  walls,  deadening  the 
floors  with  terra  cotta  blocks,  and  steel  joists  and  girders,  it 
seems  like  folly  to  put  materials  on  a  roof,  the  most  exposed 
part  of  the  building,  that  will  not  resist  the  least  heat,  but  rather 
attract  fire  from  adjoining  buildings,  and  often  when  more 
than  a  square  away.  Many  of  you  have  had  fires,  and  know 
what  it  means  to  be  burned  out ;  and  all  of  you  pay  insurance, 
and  know  what  a  heavy  tax  that  is.  Jn  Germany,  where  build- 
ings are  constructed  under  government  inspection,  with  all  pos- 
sible protection  against  fire,  and  where  tile  roofs  are  universal, 
the  rate  of  insurance  is  one-tenth  of  what  it  is  in  this  country. 
A  risk  that  will  cost  one  dollar  there  will  cost  ten  dollars  here, 
and  losses  by  fire  there  are  as  one  to  one  hundred  here.  In  the 
last  seventeen  years,  in  the  United  States,  the  losses  by  fire 
were  $1,818,323,306.00 — more  than  the  present  National  debt. 
In  the  year  1891  the  loss  was  $143,764,967.00,  in  23,313  fires. 
Of  these  fires  44  brick  and  tile  works  were  destroyed.  981  fires 
were  caused  by  sparks  from  locomotives  and  flues,  on  which 
the  loss  was  $4,506,184.00.  12,394  business  failures  were 
traced  directly  to  the  loss  by  fires  in  1891.  Last  year  $40,- 
600,000.00  of  property  was  destroyed  by  fire  that  did  not  orig- 
inate on  the  premises,  or  by  exposure  to  adjoining  property. 
The  percentage  of  loss  in  1891  that  originated  on  the  premises 
was  7 1  A,  and  by  exposure,  28 rV.  This  is  a  fearful  re- 
cord of  loss  by  fire,  and  the  worst  of  it  is,  every  one  of  you  have 
to  pay  part  of  it,  whether  the  property  was  insured  or  not. 
This  is  only  the  money  value  of  the  loss,  and  if  the  loss  in 
time  and  business,  by  men  thrown  out  of  work,  was  estimated, 
36 


562  BRICK,  TILES    AND   TERRA-COTTA. 

it  would  probably  be  more  than  doubled.  Now,  as  it  is  ad- 
mitted and  unquestioned  fact  that  there  is  no  material  that 
affords  so  certain  a  protection  from  fire  as  burned  clay,  you  see 
the  value  tile  has  for  roofing.  Nearly  one-third  the  fires,  and 
one-third  the  loss  in  1891,  was  from  outside  exposures,  that 
might  and  would  have  been  saved  if  the  buildings  had  been 
covered  with  tile.  Can  any  stronger  argument  be  used  in  cov- 
ering houses  with  tile  ? 

Another  valuable  quality  in  the  clay  roof  covering  is  that  it 
is  a  non-conductor.  This  is  evidenced  by  the  use  of  porcelain 
insulators  on  electric  lines.  They  are  considered  just  as  good 
for  this  purpose  as  glass.  Now  it  is  as  important  in  building  a 
house  to  keep  out  the  heat  in  summer  as  to  keep  it  in  in  winter. 
It  is  the  rule  that  the  attics  of  our  houses,  and  especially  if  cov- 
ered with  slate,  are  as  hot  as  ovens ;  and  as  long  as  a  single 
floor  and  coat  of  plaster  only  separate  the  attic  from  the  sleep- 
ing room,  the  temperature  in  the  latter  nearly  equals  that  of 
the  former.  Nothing  so  effectually  overcomes  this  as  a  tile 
roof,  which  neither  attracts  the  heat  nor  retains  the  frost.  The 
sleeping  rooms  in  a  house  covered  with  tile  are  always  com- 
fortable— cooler  in  summer  and  warmer  in  winter. 

The  day  for  boring  auger  holes  with  gimlets  is  past.  In  all 
mechanical  business,  and  particularly  in  clay  industries,  in  these 
days,  it  takes  capital  to  start  a  business  and  carry  it  on.  The 
profit  is  made  to-day  on  the  amount  of  business  done — on  the 
use  of  the  best  machinery,  and  appliances,  and  conveniences 
for  handling  and  shipping.  Little  fish  can't  swim  safely  in 
streams  where  big  fish  live  and  thrive.  The  point  I  want  to 
make  is,  that  to  be  successful  in  any  branch  of  the  clay  busi- 
ness, in  these  days,  you  must  have  money  enough  to  get  the 
best  machinery,  and  to  meet  all  bills  until  your  business  gets 
on  a  paying  basis.  This  is  particularly  true  in  the  tile  business. 
Many  have  the  idea  that  the  roofing  tile  business  is  a  small  one — 
that  it  is  like  the  drain  tile  business — a  neighborhood  affair.  It  is 
not.  It  is  a  business  as  large  as  you  have  the  money  and  busi- 
ness brains  to  make  it.  No  tile  factory  I  know  of  in  this  coun- 


MANUFACTURE   AND    GLAZING    OF    ROOFING   TILES.       563 

try  has  been  able  to  keep  a  stock  on  hand  to  supply  immediate 
demands.  It  has  been  necessary  to  order  the  tile  for  the  roof 
before  the  cellar  was  dug,  and  then  often  wait  weeks  or  months, 
with  the  building  exposed  to  the  weather,  before  you  get  them. 
The  consequence  of  this  uncertainty  and  delay  has  compelled 
architects  and  owners  to  substitute  other  roof  covering — they 
would  not  be  deviled  to  death  waiting.  Tile  will  stand  ship- 
ping— the  business  is  a  large  and  growing  one,  but  it  must  not 
be  started  and  carried  on  in  the  gimlet  principle. 

You  have  read  in  your  papers  of  the  trials  and  tribulations  of 
the  man  who  tried  to  run  a  brickyard.  He  had  read  about 
making  brick  in  the  papers,  and  therefore  knew  all  about  it. 
All  he  had  to  do  was  to  buy  a  machine,  start  a  yard,  and  the 
machine  would  make  the  brick.  He  tells  of  his  troubles ;  the 
time  lost,  money  lost,  brick  lost,  temper  lost,  and  even  his  re- 
ligion lost,  before  he  succeeded  in  becoming  a  good  brick- 
maker.  If  this  is  true  of  brick,  it  is  doubly  true  of  tile.  It  is 
possible  some  of  you  have  had  experience  in  trying  to  make 
tile,  and  could  tell  interesting  stories  of  how  sanguine  you  were 
when  you  started  in,  and  how  disgusted  you  were  when  you 
started  out.  If  you  have  not  been  there,  others  have.  I  have 
met  them — plenty  of  them.  I  have  heard  of  men  that  could 
tell  you  all  about  making  tile — but  their  tile  never  got  on  the 
roof.  I  suppose  I  am  talking  to  practical  men,  that  can  ap- 
preciate a  practical  business  proposition.  When  I  tell  you 
that  if  you  want  to  start  in  the  tile  business,  buy  experience  and 
knowledge  from  the  successful  man,  you  will  understand  it.  If 
the  knowledge  is  of  the  right  kind  it  is  cheap  at  any  price.  It 
will  save  you  much  more  than  you  pay  for  it.  Experimenting 
costs  a  great  deal  more  than  practical  knowledge  and  experi- 
ence. The  man  that  has  the  knowledge  and  experience  has 
paid  for  it.  You  see  the  point  ? 

Will  tile  sell?  is  a  question  that  may  be  asked.  I  have  been 
in  a  position  to  know  they  will.  Of  course  tile,  as  compared 
with  other  roofs,  is  not  a  cheap  roof,  and  will  not  be  used  on 
the  cheaper  class  of  buildings.  But  tile  has  qualities  for  roof- 


564  BRICK,  TILES   AND  TERRA-COTTA. 

Ing  no  other  material  has,  and  if  a  tile  looks  well,  has  the  fire 
and  frost  properties,  can  be  laid  at  a  small  cost,  is  not  too 
heavy,  and  can  be  sold  at  a  reasonable  price,  every  building 
that  has  valuable  records  and  property  to  protect,  churches, 
school  houses,  railroad  depots,  and  elegant  private  residences, 
will  use  them.  The  trouble  is  not  to  sell  them,  but  to  have 
them  to  sell ;  so  that  architects  and  builders  know  they  can  get 
them,  when  wanted,  without  delay.  I  know  what  I  am  saying 
when  I  tell  you  the  only  trouble  about  selling  tile  is  in  keeping 
a  stock  on  hand  to  supply  the  demand.  Tile  is  the  coming 
roof  in  the  United  States. 

I  have  shown  you  from  the  best  authority  that  there  is  no 
roofing  material  equals  tile.  Slate  is  the  next  best,  and  in 
comparing  prices  with  an  inferior  article,  you  must  bear  in 
mind  the  relative  qualities.  The  American  Architect  quotes 
prices  on  building  materials.  In  looking  at  the  quotations  on 
slate  in  Chicago,  to  builders  and  contractors,  the  prices  range 
from  $5.50  to  $14.00  per  square.  Red  slate  is  $12.00  to 
$14.00  and  unfading  black  and  purple  $7.10  to  $9.00.  Now 
the  tile  made  under  the  patents  of  the  Clay  Shingle  Company 
can  be  sold,  at  a  good  profit,  for  $8.00  per  square,  and  can  be 
laid  on  the  roof  as  cheap  or  cheaper  than  slate ;  so  you  see  the 
modern  tile,  made  by  machinery,  having  all  the  valuable  quali- 
ties of  the  old  tile,  has  the  advantage  in  weight  and  price  over 
the  better  class  of  slate.  With  these  points  in  their  favor,  who 
can  say  that  tile  is  not  the  coming  roof  ? 

GLAZING  OF  ROOFING  TILES,  ETC.* 

Most  varieties  of  clay,  particularly  those  which  burn  red, 
permit,  even  when  thoroughly  burnt,  the  percolation  of  more 
or  less  water.  Hence,  it  is  frequently  observed,  that  new  roof- 
ing tile,  especially  when  not  previously  soaked,  permit  the 
rain  to  pass  through  to  such  an  extent  that  the  water  not  only 
appears  in  drops  on  the  lower  surface,  but  in  sufficient  quantity 
to  wet  the  floor  below.  To  be  sure,  the  interspaces  in  the  clay 

*  From  Waldegg's  German  Work  on  Brick  and  Tile. 


MANUFACTURE   AND    GLAZING  OF   ROOFING  TILES.       565 

are  gradually  closed  by  mud  deposited  by  the  water,  whereby 
the  tiles  after  some  time  become  impervious.  But  the  same 
mud  also  produces  upon  the  entire  surface  of  the  tiles,  especi- 
ally if  the  latter  are  not  perfectly  smooth,  a  coating  which  takes 
up  dust  and  dirt.  Hence,  it  frequently  happens  that  nearly  all 
the  tiles,  particularly  upon  low  roofs,  are  covered  with  thick 
moss,  which  retains  moisture,  and  the  tiles  on  such  places  must 
necessarily  rot.  The  partial  object  of  glazing  roofing  tiles  is  to 
prevent  this  evil. 

Besides,  the  great  roof  surfaces  of  deep  buildings,  such  as 
churches,  are  monotonous,  they  offering  to  the  eye  but  little 
interruption.  This  is  still  more  the  case  in  brick-work,  where 
the  colors  of  the  building  are  repeated  in  the  roof.  In  the 
middle  ages  this  evil  was  also  recognized  and  overcome  by 
covering  the  roof  with  glazed  tiles  of  different  colors.  In  build- 
ing the  Ludwig  church,  at  Munich,  *V.  Gaertner  pursued  the 
same  course,  and  in  covering  the  roof  with  glazed  tile  produced 
an  effect  which  admits  of  comparison  with  a  pearl-embroidered 
carpet. 

Glazing  consists  in  giving  the  exterior  surface  of  the  tiles  a 
coating,  which  at  the  temperature  required  for  burning  is  con- 
verted into  a  glass-like  mass.  Hence  the  glaze  is  a  substance 
entirely  different  from  the  mass  of  the  tile,  and  its  durability 
and  solidity  depend  much  on  the  manner  of  its  combination 
with  the  tile.  The  object  of  the  glaze  is,  therefore,  on  the  one 
hand,  to  decorate  the  tile,  and  on  the  other,  to  render  its  sur- 
face impervious.  The  glaze  mostly  consists  of  a  lead-glass  col- 
ored as  desired  by  the  addition  of  metallic  oxides.  For  ordi- 
nary pottery  the  proportion  of  silica  to  lead  oxide  is  about  1:2; 
i.  e.  mix  about  I  part  by  weight  of  sand  (frequently  mixed  with 
some  clay)  with  double  the  weight  of  litharge  or  minium.  The 
more  sand  in  proportion  to  lead  oxide  is  taken  the  more  diffi- 
cult to  fuse  the  glaze  becomes.  Litharge  or  minium  melts  at  a 
comparatively  low  temperature  and  in  a  melted  state  dissolves 
the  admixed  sand,  forming  with  it,  if  the  substances  are  pure, 
a  white  transparent  glass.  According  to  the  constitution  of  the 


566  BRICK,  TILES   AND   TERRA-COTTA. 

sand  a  varying  quantity  by  weight  of  it  is  at  the  same  time  dis- 
solved by  the  melting  lead  oxide.  If  the  sand  is  coarse- 
grained, so  that  the  surface  exposed  to  the  attack  of  the  lead 
oxide  is  a  small  one,  as  compared  with  the  mass  of  the  sand, 
far  less  of  it  will,  of  course,  be  in  the  same  time  dissolved 
than  when  the  exposed  surface  is  greater.  Hence  the  finer  the 
sand,  the  greater  the  quantity  which  will  in  the  same  time  be 
dissolved  by  the  lead  oxide.  For  this  reason  sand  as  finely  di- 
vided as  possible  is  a  chief  condition  in  preparing  glaze,  be- 
cause if  the  grain  is  too  coarse,  the  entire  quantity  of  sand  is 
not  dissolved,  coarser  or  finer  grains,  according  to  the  time 
during  which  the  lead  oxide  was  allowed  to  act  upon  the  sand, 
remaining  behind. 

Of  still  greater  influence  than  the  fine  division  of  the  sand  is 
its  chemical  condition,  since  its  fusing  point  plays  a  very  im- 
portant role  as  regards  the  quantity  which  during  the  same 
time  can  be  dissolved  by 'the  action  of  the  melted  lead  oxide. 
Pure  silica  in  the  form  of  finely  pulverized  quartz,  flint,  etc.,  is 
not  fusible,  and  hence  will  require  the  most  time  for  solution  by 
the  lead  oxide,  because  the  latter  will  have  to  act  upon  a  per- 
fectly solid  body.  If  silica  in  the  form  of  a  fusible  mass  be  con- 
veyed to  the  lead  oxide,  a  much  larger  quantity  of  it  will  in  the 
same  time  be  dissolved,  and  it  may  be  laid  down  as  a  rule,  that 
a  greater  quantity  of  silica,  of  the  same  degree  of  fineness,  will 
in  the  same  time  be  dissolved  by  an  equal  quantity  of  lead  oxide 
(as  well  as  of  other  fluxes),  the  more  readily  fusible  the  mass  is 
by  means  of  which  it  is  introduced.  Nature  furnishes  us  with 
an  abundance  of  substances  possessing  all  possible  melting 
points,  which,  with  a  high  content  of  silica,  are  more  or  less 
readily  fusible. 

There  are  sands  with  a  very  high  content  of  silica  which 
already  slag  (soften)  at  about  1000°  C.  and  hence  readily 
dissolve  in  fluxes.  Such  sands,  highly  valued  for  glazing 
purposes,  are,  for  instance,  found  at  Machlin,  in  Mecklenberg, 
and  at  Fuerstenwalde.  These  sands  contain  about  85  per  cent, 
silica,  7.5  alumina,  and  4  to  5  fluxing  agents  (ferric  oxide,  lime, 


MANUFACTURE   AND    GLAZING    OF   ROOFING  TILES.        567 

magnesia,  and  alkalies),  and  on  account  of  their  ready  fusibility 
and  physical  constitution  (they  contain  many  fine  scales  of 
mica,  which  offer  a  large  surface  to  the  solution),  they  dissolve 
readily  and  rapidly  in  fluxing  agents.  Besides  these  there  are 
many  clays  with  a  comparatively  high  content  of  silica  which 
fuse  more  or  less  readily.  There  are  clays  fusing  at  from 
i, 000°  to  i, 1 00°  C.,  which,  in  case  such  high  temperatures  are 
used  in  burning,  yield  by  themselves  good  glazes,  provided  it 
does  not  matter  as  to  color,  and  that  the  sole  object  is  to  make 
the  articles  impervious  (earthy  glazes  for  water-pipes,  pottery, 
roofing  tile,  etc.). 

In  the  great  abundance  of  substances  rich  in  silica  and  more 
or  less  readily  fusible,  which  on  the  one  hand  are  furnished  us 
by  nature,  and  on  the  other  as  waste  (slag,  broken  glass,  etc.), 
by  certain  industries,  there  are  so  many  suitable  for  glazes  that 
with  some  professional  knowledge  ,a  suitable  choice  can  be 
readily  made,  especially  as  the  readily  fusible  fluxes  (litharge, 
potash,  soda,  boric  acid,  etc.)  offer  means  of  bringing  the  fusi- 
bility of  the  selected  materials  within  a  narrow  limit  and  thus 
exactly  fit  the  fusing  point  of  the  glazing  masses  to  the  burning 
temperature  of  the  kilns.  With  glazes  for  the  purpose  of  deco- 
ration the  conditions  are  much  more  difficult,  the  choice  of  sub- 
stances through  which  the  silica  can  be  introduced  being  very 
limited.  In  this  case  not  so  much  stress  can  be  laid  upon  the 
ready  solubility  in  fluxes  as  upon  the  purity  of  the  materials. 
The  naturally  occurring  substances  rich  in  silica  which  are 
readily  fusible,  generally  contain  more  or  less  iron  by  which 
they  are  colored  dark.  Hence  if  pure  colors  are  to  be  obtained, 
sands,  etc.,  containing  iron  have  to  be  avoided  and  substances 
free  from  iron,  but  more  difficult  to  fuse,  selected.  For  glazes 
which  are  to  serve  for  the  pupose  of  decoration  and  show  a 
determined  color,  sand  free  from  iron  (mica  sand  of  the  best 
quality,  finely  pulverized  quartz  or  flint,  etc.)  will  have  to  be 
used,  and  the  proportion  for  the  substances  determined  which 
is  suitable  for  the  burning  temperature  prevailing  in  the  kiln. 
When  a  colorless  lead-glass  suitable  for  the  special  variety  of 


568  BRICK,  TILES   AND   TERRA-COTTA. 

clay  and  the  burning  temperature  employed  has  been  found, 
the  various  shades  of  color  are  obtained  by  mixing  the  corres- 
ponding metallic  oxides  in  proportions  to  be  determined  with 
the  glaze. 

For  dark-brown  to  black,  pyrolusite  (peroxide  of  manganese) 
is  used;  ior  green  to  black,  oxide  of  copper  or  chromium;  for 
blue,  cobalt  oxide ;  for  yellow,  atimony  oxide ;  for  red,  ferric 
oxide. 

The  application  of  the  glaze  to  the  tiles  is  as  a  rule  effected 
by  dipping,  or  to  depressed  places  in  ornamental  or  shape 
brick,  or  in  architectural  terra-cotta,  etc.,  by  means  of  a  brush, 
the  articles  being  dipped  either  in  a  dry  state,  or  still  better 
after  having  been  burnt.  If  the  surface  of  the  tile  is  not  suffi- 
ciently porous  for  the  glaze  to  penetrate,  a  cementing  agent 
(paste,  gum  arabic,  etc.)  is  added  to  the  latter  to  render  its 
adhesion  possible.  The  condition  of  the  surfaces  to  be  dipped 
or  treated  with  the  brush  should  be  uniform,  so  that  the  glaze 
may  everywhere  adhere. 

The  principal  defects  shown  by  the  glazes  after  burning  are 
fine  cracks.  To  prevent  them,  it  is  advisable  to  gradually  de- 
crease the  content  of  fluxing  agent  (litharge,  etc.)  without, 
however,  changing  the  composition  of  the  mass,  and  thus  make 
the  glaze  more  difficult  to  fuse.  The  temperature  must,  of 
course,  be  increased,  but  fine  cracks  will  thereby  be  entirely  or 
almost  entirely  prevented.  If,  however,  this  remedy  is  not  suc- 
cessful, i.e.  if  fine  cracks  still  occur  notwithstanding  the  utmost 
possible  reduction  in  the  content  of  fluxing  agent  in  the  glaze 
and  a  corresponding  increase  in  the  temperature,  changes,  as 
far  as  permissible,  must  be  made  in  the  raw  materials.  It 
should  be  endeavored  to  make  the  mass  meagre  with  quartz 
sand  or  pulverized  limestone  (chalk)  until  the  formation  of  fine 
cracks  ceases.  The  so-called  salt-glaze  is  produced  by  from 
time  to  time  throwing  salt  into  the  kiln  during  burning.  The 
salt  vaporizes  at  a  high  temperature  and  produces  a  glaze  upon 
the  surface  of  the  articles. 

The  constitution  and  preparation  of    the  clay  are  of    special 


MANUFACTURE   AND   GLAZING   OF   ROOFING  TILES.       569 

importance,  particularly  when  the  tiles  are  to  receive  a  colored 
coating  of  glaze.  In  order  to  make  the  latter  durable,  it  must 
enter  into  combination  with  the  clay  without  the  formation  of 
fine  cracks,  bubbles,  etc.  The  following  mixtures  which  have 
been  established  by  careful  tests  in  the  brickyards  of  Munich, 
fulfill  these  conditions  with  the  glazes  belonging  to  them,  and 
may  serve  as  guiding  points. 

1.  DIFFERENT    MIXTURES    FOR  THE  TILE-MASS. 

1 .  Common  clay I  part  by  volume. 

Red  clay }£    "     " 

Quartz  sand 

2.  Marl 

Quartz  sand 

3-  Marl 

Alum  earth 

Chalk. 

Quartz  sand * 

4.  Common  clay 

Red  clay 

Where  there  is  a  choice,  the  mixture  given  under  I  is  to  be 
preferred. 

II.    MIXTURES   FOR   GLAZES. 

I .   Glazes  for  Nos.  i  and  2  of  the  tile-masses. 

Lead  ashes 12  parts  by  weight. 

Silver  litharge 4      "  " 

Quartz  sand 3      "  " 

White  alum  earth 4      "  " 

Common  salt .....  2      "  " 

Powdered  glass , 3      "  "        " 

Saltpeter i      "  "        " 

2.  Glazes  for  Nos.  3  and  4.  of  the  tile-niassts. 

Litharge 16  parts  by  weight. 

Quartz  sand 5      "     "         " 

Powdered  glass 4      "     " 

Adamic  earth i      "     "         " 

The  intimate  mixture  of  the  ingredients  of  the  tile-mass  is,  of 
course,  the  first  requirement.  For  this  purpose  it  is  best  to 
finely  divide  each  ingredient  by  itself  either  by  pounding  or, 


5/0  BRICK,  TILES   AND   TERRA-COTTA. 

better,  by  rolling,  then  to  pass  it  through  a  fine  sieve,  and  after 
moistening  the  entire  mass  with  water  to  intimately  mix  it  by 
tempering  or  rolling.  The  constituents  of  the  glaze  are  also 
passed  through  a  fine  sieve  and,  after  being  intimately  mixed, 
fused  in  crucibles  to  gloss,  which,  after  cooling,  is  reduced  to  a 
fine  powder  by  grinding  with  water.  The  powder  is  then  pre- 
pared as  required  for  application  to  the  tiles. 

The  flat  tiles  which  are  generally  used  in  Munich  are 
moulded  in  the  usual  manner,  and  after  being  carefully  dried 
they  are  sharply  burnt  for  the  first  time.  To  free  the  surface 
of  the  tile  from  dust  and  other  impurities  acquired  in  burning, 
and  at  the  same  time  to  test  whether  the  tiles  contain  pieces 
of  lime,  they  are  dipped,  i.  e.,  placed  in  water,  for  one  or  two 
days.  Any  lime  present  is  thereby  slaked  and  causes  the  tile  to 
crack,  which,  of  course,  would  also  take  place  after  the  appli- 
cation of  the  glaze,  but  the  latter  would  be  lost. 

The  glazing  mass  mentioned  under  I,  yields  quite  a  white 
gloss,  the  whiteness  of  which  may  be  considerably  heightened 
by  an  addition  of  20  to  24  Ibs.  of  tin  to  every  100  Ibs.  of  lead 
before  reducing  the  latter  to  ashes.  The  coloring  of  both  glaz- 
ing masses  is  effected  by  the  following  additions,  many  tests 
being  made  as  regards  beauty,  and  especially  durability : 

r  .  To  every  10  Ibs.  of  glazing 

mass  is  added 

Dark  violet  brown K  lb-  pyrolusite. 

Violet 34  lb-  pyrolusite. 

Green 34  lb.  copper  ashes. 

Pale  blue 4^2  drachms  red  cobalt  ashes. 

Golden  yellow %  lb.  antimony. 

These  additions  are  not  fused,  but  after  pounding,  passed 
through  a  sieve,  and  then  ground  fine.  By  adding  more  or  less 
of  them  darker  or  lighter  colors  may  be  obtained.  It  may  here 
be  remarked  that  small  tests  should  be  made  with  all  colors  be- 
fore coloring  the  whole  mass  of  glaze,  because  the  materials  as 
obtained  in  commerce  vary  very  much  in  regard  to  purity ;  the 
quantity  of  pyrolusite,  for  instance,  required  for  the  production 


MANUFACTURE   AND    GLAZING   OF   ROOFING   TILES.       571 


of  one  and  the  same  color  varying  very  much  according  to  the 
source  from  which  the  material  has  been  procured. 

For  glazing,  the  surfaces  of  the  tiles  are  rubbed  clean ;  the 
glaze  is  then  applied  with  a  brush,  the  tiles  being  held  almost 
perpendicularly  over  the  vessel  containing  the  glaze.  They 
absorb  the  glaze  so  quickly  that  soon  afterward  they  may  be 
replaced  in  piles.  Formerly  the  glaze  was  applied  dry,  but 
glazing  by  the  wet  method  is  better.  With  some  experience 
and  skill  one  workman  can  glaze  from  5,000  to  6,000  tiles  a 
day.  When  the  glaze  is  applied  it  is  burnt  in  by  a  second 
slighter  burning.  In  doing  this  special  attention  must  be  paid 
to  the  degree  of  heat  in  order  to  obtain  uniform  coloring,  but 
further  details  regarding  the  operation  cannot  be  given.  An 
experiment  made  in  Munich  to  prepare  red  tiles  by  coating  the 
unburnt  clay  in  a  semi-dry,  so-called  leathery  state,  with  pul- 
verized reddle,  then  burning,  and  finally  coating  with  a  trans- 
parent glaze,  did  not  succeed,  since  the  glaze  did  not  adhere  and 
many  tiles  cracked.  But  a  red  glaze  may  be  obtained  by 
the  admixture  of  a  certain  quantity  of  pyrolusite — between  that 
required  for  dark  violet  brown  and  violet — and  maintaining  a 
fixed  degree  of  heat,  which  can  only  be  ascertained  by  experi- 
ments. 


FIG.  234. 


FIG.  235. 


FIG.  236. 


The  illustrations,  Figs.  234,  235,  and  236,  show  the  form 
and  size  of  roofing-tiles,  as  well  as  the  mode  of  tiling  custom- 
ary in  Munich.  Since  after  tiling  the  roof,  the  surface  of  the 


57-2  BRICK,  TILES   AND   TERRA-COTTA. 

tile  which  remain  visible,  form  small  squares  with  sides 
inches  long,  it  is  possible  to  produce,  by  the  use  of  different 
colors,  designs  which  relieve  the  monotony  of  the  surfaces.  It 
may  further  be  remarked  that  on  account  of  the  considerable 
height  and  the  small  size  of  the  squares,  the  indentations  of  the 
horizontal  and  perpendicular  lines  cannot  be  seen,  but  appear 
as  inclined  lines. 

For  plain  glazing  (dark  brown  or  black)  roofing-tiles  in  a 
more  simple  manner,  it  is  not  necessary  to  first  burn  the  tiles, 
but  the  glaze  may  be  applied  to  the  crude  article.  For  the 
glaze  it  is  best  to  use  the  Dutch  directions,  according  to  which 
3  Ibs.  of  pyrolusite  are  taken  for  every  20  Ibs.  of  litharge,  and 
so  much  clay  is  added  that  a  ball  formed  of  the  clay  floats  in 
the  glazing  mass.  For  ordinary  lead  ore  6  per  cent,  pyrolusite 
suffices,  and  the  glaze  becomes  perfectly  black  by  adding  1.5 
to  2  per  cent,  of  copper  oxide.  In  all  compositions  for  glaze 
special  attention  must  be  "paid  that  the  mixture  is  not  too 
readily  fusible,  so  the  tile  itself  has  a  chance  to  become  hard 
by  burning.  Neither  should  it  be  too  refractory,  as  otherwise 
the  tile  would  be  over-burnt  before  the  glaze  fuses.  Hence,  an 
accurate  knowledge  of  the  clay  is  necessary,  and  it  should  be 
determined  by  experiments  how  great  an  addition  of  one  or  the 
other  kind  of  lead  oxide  it  will  bear  in  order  to  obtain  the  de- 
sired degree  of  fusibility.  If  pyrolusite  is  also  to  be  added, 
the  quantity  of  sand  or  silica  must  be  sufficiently  reduced  in 
order  to  restore  the  proper  proportions.  It  must  also  be  re- 
membered that  pyrolusite  makes  the  glaze  far  more  refractory 
than  silica  or  sand,  which  readily  fuse  with  the  lead  to  a  glass, 
and  that  hence  the  quantity  of  the  one  cannot  be  exchanged 
for  that  of  the  other. 

The  above  mentioned  substances  are,  each  by  itself,  reduced 
to  as  fine  a  state  as  possible,  then  weighed  off  in  accordance 
with  the  above  stated  proportions  and  then  ground,  first  each 
by  itself  and  then  mixed  together,  in  a  glaze-mill  with  water 
containing  fine  clay  in  solution,  until  they  feel  milky  to  the 
touch  and  nothing  like  sand  can  be  detected.  The  rapid  pro- 


MANUFACTURE   AND   GLAZING  OF   ROOFING  TILES.       5/3 

gress  of  this  operation  is  chiefly  dependent  on  the  quality  of 
the  mill-stones  and  the  arrangement  of  tbe  mill.  Ordinary 
glaze-mills  are  of  fine  sand-stone,  hard  lime-stone,  or  granite. 

Before  applying  the  glaze,  the  surfaces  of  the  raw  tiles  are 
rubbed  clean,  to  prevent  the  glaze  from  being  contaminated  by 
sand  or  dust.  When  sufficient  tiles  have  thus  been  prepared, 
the  workman  places  himself  between  the  tiles  and  a  frame. 
Upon  a  bench  in  front  of  him  stands  a  shallow  vessel  of  a  wide 
circumference  filled  with  glaze.  This  vessel  is  called  the  glaze- 
back  and  may  be  of  wood  or,  still  better,  of  earthenware. 
After  stirring  the  glaze  with  a  large  wooden  spoon,  the  work- 
man, taking  with  the  left  hand  a  tile  by  its  upper  portion,  and 
holding  it  almost  perpendicularly  over  the  glaze-back,  places 
the  spoon  filled  with  glaze  about  I  J^  inches  below  the  upper 
edge  of  the  tile  and  moves  it  from  the  left  to  the  right,  allowing 
the  glaze  in  the  spoon  to  run  over  the  tile.  If  the  glaze  is  of 
the  proper  consistency  it  is,  in  this  manner,  very  uniformly 
distributed  over  the  entire  surface  of  the  tile.  A  test  with  the 
finger-nail  is  from  time  to  time  made  to  see  whether  the  glaze 
has  still  the  requisite  thickness,  water  or  thicker  glazing  mass 
being  otherwise  added.  The  tiles  absorb  the  glaze  with  such 
rapidity  as  to  permit  of  them  being  soon  afterward  replaced  in 
piles.  The  finer  the  glaze  has  been  ground,  the  better  it  re- 
mains suspended  in  the  water  and  the  more  rarely  it  requires  to 
be  stirred  up  from  the  bottom.  A  further  reason  for  the  ne- 
cessity of  grinding  the  glaze  as  fine  as  possible  is  that  other- 
wise the  pyrolusite  does  not  thoroughly  mix  with  the  lead  ore, 
which  causes  the  appearance  of  streaks  and  stains  after  burning. 
With  some  experience  one  workman  can  coat  5,000  to  6,000 
tiles  with  glaze  per  day. 

Regarding  tiles,  the  question  whether  it  is  more  advanta- 
geous to  glaze  the  crude  or  burnt  articles  is  not  so  easily 
answered  as  for  finer  clay  ware.  When  the  tiles  have  been 
properly  set  in  the  kiln  and  the  fire  is  properly  conducted,  the 
refuse  by  breakage,  cracking,  etc.,  should  not  be  considerable. 
But  with  tiles  the  mishaps  by  fusing  and  baking  together. are 


574  BRICK,  TILES   AND   TERRA-COTTA. 

more  dangerous.  With  well-constructed  kilns  the  first  should 
scarcely  happen,  especially  when  heating  with  small  fires  and 
the  coal  cannot  directly  act  upon  the  tiles.  The  latter  may  be 
avoided:  I.  By  not  applying  the  glaze  too  thick;  2.  By  the 
upper  portion  of  the  tile,  where  the  knob  of  its  neighbor  leans 
against  it,  being  left  free  from  glaze;  3.  By  setting  the  tiles  as 
perpendicularly  as  possible  so  that  they  touch  neither  with 
their  surfaces  nor  with  their  lateral  sides,  and  so  firmly  that 
they  cannot  turn  over  during  burning;  and  4.  By  wiping  off 
with  the  hand  the  greater  portion  of  the  glaze  from  the  base  of 
the  tile,  so  that  there  is  no  danger  of  their  baking  together  on 
that  point.  With  a  second  burning  the  tiles  are,  however,  ex- 
posed to  the  same  mishaps,  and  the  consumption  of  double  the 
quantity  of  fuel  is  mere  waste. 

The  following  process  may  also  be  recommended  as  the  most 
simple  glaze.  Scatter  finely  sifted  unburnt  lime  and  ashes  over 
the  half-dried  tile,  rub  in  well,  and  then  allow  the  tiles  to  dry 
further.  This  mixture  is  a  slight  fluxing  agent  and  produces  a 
glaze  upon  the  surface. 

Glazing  with  salt  is  effected  by  throwing  the  salt  in  the  kiln, 
when  burning  is  finished  so  far  that  the  kiln  is  to  be  closed  for 
cooling  off.  Since  by  this  process  a  uniform  glazing  of  all  the 
tiles  cannot  be  effected,  it  is  preferable  to  prepare  a  supersatu- 
rated solution  of  the  salt  in  water  and  apply  it  to  the  tile  before 
setting  them  in  the  kiln. 

Regarding  the  setting  of  glazed  tiles  it  may  be  remarked  that 
a  kiln  should  never  be  entirely  set  with  them ;  because  even 
with  the  best  kiln  it  is  impossible  to  distribute  the  heat  so  uni- 
formly as  to  avoid  fusing  together,  if  it  is  insisted  upon  to  every- 
where fuse  the  glaze. 

RAW   GLAZING   OF   DUTCH   TILES. 

The  object  of  raw  glazing  of  Dutch  tiles  is  to  apply  the  glaze 
to  the  green  tile  and  to  burn  the  clay  mass  and  glaze  in  one 
fire.  All  endeavors  previously  made  to  introduce  raw  glazing 
failed  on  account  of  the  glaze  readily  falling  off  from  the  un- 


MANUFACTURE   AND    GLAZING   OF   ROOFING  TILES.        575 

burnt  tile  when  touched ;  further,  on  account  of  the  glaze  con- 
tracting in  burning  and  leaving  unglazed  places.  These  diffi- 
culties are  overcome  by  the  following  process : 

Glue-water  of  about  5°  Be.  is  poured  over  the  tile,  which 
must  be  air-dry  and  free  from  dust ;  the  tile  is  then  allowed  to 
dry  in  the  air  for  a  few  hours ;  potters'  glazing  wash  is  then 
applied  to  the  tile  thus  prepared. 

MEISSEN  MASSES  FOR  DUTCH  TILES. 

Chamotte  Mass. — One  part  by  measure  of  chamotte,  2  of 
Lothain  clay. 

White  Covering  Mass. — Twenty  pounds  of  Kaschka  clay,  10 
pounds  of  elutriated  kaolin,  and  5  pounds  of  feldspar. 

Silver  Gray  Covering  Mass. — One  hundred  and  twenty-five 
pounds  of  kaolin,  75  pounds  of  Lothain  clay,  55  pounds  of 
Mattowitz  clay,  0.5  pound  of  pyrolusite,  and  7.5  pounds  of 
smalt. 

Fawn-Color  Covering  Mass. — Fifty  pounds  of  Lothain  clay, 
25  pounds  of  Mattowitz  clay,  4  pounds  of  pyrolusite,  and  y2 
pound  of  smalt. 

Yellow  Covering  Mass. — Fifty  pounds  of  Lothain  clay,  12.5 
pounds  of  Wahlstadt  clay,  and  some  ordinary  clay. 

Brown  Covering  Mass. — Fifty  pounds  of  Lothain  clay,  10 
pounds  of  bole,  and  7.5  pounds  of  pyrolusite. 

Green  Covering  Mass. — Ten  pounds  of  Kaschka  clay,  2*^ 
pounds  of  Lothain  clay,  copper  scales  2  to  3  pounds. 

Bhie  Covering  Mass. — White  covering  mass  of  the  composi- 
tion given  above  100  pounds,  smalt  20  to  25  pounds,  and  white 
chamotte,  50  pounds. 

Mass  for  Mending  before  Glazing. — Glowed  kaolin,  I  part  by 
measure ;  feldspar,  ^ ;  whiting,  ^ ;  crude  kaolin,  2. 

Cheap  Glaze  Especially  for  the  Colored  Mass. — One  part  by 
measure  of  litharge,  and  I  ^  to  I  y2  of  sand. 

Finer  Glaze  for  White  Tiles. — White  quartz  sand,  24  pounds  ; 
litharge,  10  pounds;  chalk,  6^  pounds;  borax,  6  pounds; 
soda,  3  pounds;  glowed  white  clay,  3  pounds;  feldspar,  2^£ 


576  BRICK,  TILES   AND   TERRA-COTTA. 

pounds,    and    J^  ounce  of   cobaltic    oxide.     The    mixture    is 
fritted  and  then  ground  together  with  60  pounds  of  red  lead. 

GLAZES   FOR   DUTCH   TILES. 

Kraetzer  recommends  the  following  compositions : 

1.  White   Glaze. — Stir    together   120  parts   of  concentrated 
solution  of  soda  water-glass  and  milk  of  lime  (7^  to  12  parts 
of  lime)  until  the  mixture  is  perfectly  dry;    then  pulverize, 
grind  and  sift.     The  crude  tiles   are  either  brushed  over  with 
water-glass  solution  or  the  powder  moistened  with  water-glass 
solution   is    applied    as    glaze  and  burnt.     Potash,  100  parts; 
Chile  saltpetre,  12^,  and  lime,  25,  fused  together,  pulverized 
and  mixed  with  water-glass  solution,  may  be  worked   in    the 
same  manner.  , 

2.  Deep  Red  Glaze. — Finely  pulverized  white  glass,  15  parts; 
pulverized  borax,  7)^  ;   whiting,  5  ;  Chile  saltpetre,  j£  ;   purple 
of  cassius,  2^/2',   fused  together,  pulverized  and  applied  with 
water-glass  solution. 

3.  Dark  Red  Glaze. — Glass,  24  parts;   soda,  12;   borax,  9; 
red  lead,  9 ;  Chile  saltpetre,  4 y2  ;  antimony,  3/^  ;  purple  of  Cas- 
sius, 3  ;   sal  ammoniac,  3  ;   fused  together,  pulverized  and  ap- 
plied with  water-glass  solution. 

4.  Azure  Blue  Glaze. — Glass,   1 6  parts;   soda,  5^5   borax, 
4;   calcined  bones,   2^;   Chile  saltpetre,  i^;    cobaltic  oxide, 
I  y^  ;   fused  together,  pulverized  and  applied  with  water-glass 
solution. 

According  to  other  statements,  a  good  glazing  mixture  is 
obtained  by  carefully  burning  60  parts  of  lead  and  40  of  tin. 
Fuse  100  parts  of  the  ash  thus  obtained  with  50  parts  of  sand 
free  from  iron,  50  parts  of  common  salt,  20  of  feldspar,  6  of 
saltpetre,  and  6  of  litharge.  The  fused  mass  is  ground.  If  for 
some  masses  this  glaze  should  prove  too  liquid,  so  that  it  runs  off, 
take  for  the  above  mixture  60  parts  of  sand  and  25  to3<D  parts 
of  feldspar. 


MANUFACTURE   AND    GLAZING   OF   ROOFING  TILES. 
GLAZES    FOR   ROOFING- TILES.  * 

Roofing- tiles  are,  as  a  rule,  only  glazed  when  it  is  expected  to 
impart  to  them  thereby  greater  resistance  to  the  weather,  or  to 
produce  certain  decorative  effects.  Hence  dark  glazes  are 
frequently  demanded,  if  only  for  the  reason  that,  as  regards 
roofing-tiles,  we  have  generally  to  deal  with  quite  dark-colored 
clays.  But  such  tiles  should  only  be  glazed  if  they  possess  the 
degree  of  solidity  absolutely  required  for  it.  It  is  well  known 
that  slightly  burned  tiles,  when  glazed  and  exposed  to  the 
weather,  scale  off,  as  a  rule,  in  a  short  time,  and  hence  are  not 
improved  by  glazing.  It  is,  therefore,  necessary  that  tiles 
which  are  to  be  glazed  must  be  burned  hard,  at  least,  medium 
hard  ;  or  still  better,  that  they  are  clinkers.  Many  proprietors 
of  brick-yards  seem  to  be  of  the  opinion  that  tiles  may  be 
burned  slightly,  and  then  provided  with  a  glaze  to  make  them 
more  durable.  Such,  however,  is  not  the  case.  If  a  tile  is 
saturated  with  water  and  allowed  to  freeze,  it  will  be  observed 
that  small  sticks  of  ice  are  forced  from  all  the  small  pores, 
which  is  due  to  the  expansion  water  undergoes  in  freezing.  The 
sticks  of  ice  forced  out  will  be  the  thinner,  the  finer  the  pores, 
and  the  thicker,  the  coarser  the  pores.  This  will  be  especially  ob- 
served in  calciferous  washed  clays.  The  ice,  under  pressure,  acts 
like  a  fluid,  and  passes  out  through  the  fine  openings.  Now,  if 
these  openings  are  covered  by  a  glaze  which  does  not  firmly  ad- 
here to  the  tile,  and  the  quantity  of  water  is  quite  large,  entire 
portions  of  it  are  forced  off.  Hence,  since  it  is  generally  en- 
deavored to  burn  glaze  and  tile  in  the  same  burning,  the  fusing 
point  of  the  glaze  must  be  arranged  in  accordance  with  the 
slagging  point  of  the  clay.  Now  the  glazes  themselves,  es- 
pecially the  readily  fusible  ones,  are  not  always  capable  of  re- 
sistance, but  are  frequently  decomposed  by  atmospheric  influ- 
ences. Thus,  for  instance,  alkalies  are  lixiviated  from  the  layer 
of  glaze  by  the  influence  of  the  atmosphere.  The  layer  of  glaze 

*  An  address  delivered  before  the  General  Convention  of  the  German  Society  for 
the  Fabrication  of  Brick,  Clay  Wares,  Lime  and  Cement,  by  Prof.  Dr.  H.  Seger. 

37 


5/8  BRICK,  TILES   AND   TERRA-COTTA. 

is  thereby  loosened,  becomes  mottled,  changeable,  full  of 
cracks,  and  finally  the  entire  glaze  scales  off.  Such  glazes  will 
have  to  be  examined,  as  is  done  with  glasses  in  which  the  ac- 
tion of  the  atmosphere  upon  the  surface  has  also  to  be  inquired 
into.  Professor  Weber  has  proposed  an  excellent  method  of 
testing  glasses  as  to  their  power  of  resistance  against  the  atmos- 
phere, which  I  have  also  used  for  glazes.  Professor  Weber 
proceeds  from  the  fact  that  the  atmospheric  influences  are 
much  stronger  by  taking  substances  which  act  more  energeti- 
cally than  carbonic  acid  and  water.  He  therefore  places  the 
glasses  under  a  bell  in  which  is  a  vessel  with  concentrated 
hydrochloric  acid.  The  acid  begins  to  etch  the  surface  much 
more  rapidly  than  the  carbonic  acid  of  the  air,  and  if  the  glass 
is  destructible,  such  destruction  takes  place  in  a  very  short  time 
by  a  slight  efflorescence  of  separated  silica  showing  itself  upon 
the  surface. 

The  nature  of  the  glazes  to  be  used  depends  on  the  temper- 
ature they  are  to  sustain.  With  low  temperatures,  glazes  con- 
taining lead  will  have  to  be  used,  because  there  are  no  glazes 
free  from  lead  for  the  lowest  temperatures  employed.  The 
glazes  used  in  pottery  are  simple  lead  silicates.  They  are  the 
most  readily  fusible  glazes  and  occur  also  in  the  manufacture  of 
tiles. 

As  regards  their  content  of  silica  they  vary  from  a  sesqui- 
silicate  to  a  trisilicate,  which  at  the  same  time  contains  alumina ; 
the  richer  in  silica,  the  more  refractory  they  are.  The  com- 
position of  the  most  readily  fusible  and  the  most  refractory  lead 
glazes  may,  according  to  the  ratio  of  the  weight  of  the  sep- 
arate constituents,  be  represented  as  follows : 

Readily  fusible  glaze — 1.0x223  oxide  of  lead,  1.5  x  60  silica. 

Refractory  glaze — o.i  x  94  potash,  0.2  x  56  lime,  0.7  x  223 
oxide  of  lead,  0.3  x  101  alumina,  3.0  x  60  silica. 

The  glazes  employed  will,  as  a  rule,  lie  between  these  two 
compositions.  The  degree  of  refractoriness  of  the  glaze  which 
is  required  will  of  course  have  to  be  taken  into  consideration, 
and  hence,  these  numerical  values  may  and  must  be  extremely 


MANUFACTURE   AND    GLAZING   OF   ROOFING   TILES.        579 

varied.  When  in  glazing  tiles  color,  and  especially  a  dark 
color,  is  the  chief  requisite,  the  clay  at  the  disposal  of  the  man- 
ufacturer will,  as  a  rule,  be  utilized,  in  receiving  simply  an  ad- 
dition of  oxide  of  lead,  whereby  the  action  of  the  ferric  oxide 
in  the  clay  as  a  yellow  or  broom  coloring  agent  has  to  be  taken 
into  consideration.  No  other  substances  require,  as  a  rule,  to 
be  added.  Boric  acid,  especially,  should  be  avoided,  since 
glazes  containing  boric  acid  have  always  to  be  fritted  in,  which 
cannot  be  recommended  for  glazing  tiles,  since  the  glaze  should 
be  as  cheap  as  possible.  For  colored  glazes  the  color  of  the 
tile  must  first  be  covered  with  a  white  layer,  glazes  containing  tin 
being  best  for  this  purpose.  The  application  of  a  white-burn- 
ing clay  to  the  clay  cannot  be  recommended.  The  average 
composition  of  those  white  enamels,  will  also  serve  for  the 
preparation  of  ordinary  faience.  Dutch  tiles,  etc.,  may  be 
given  as  follows :  9.5x94  potash,  0/6x223  oxide  of  lead,  o.2x 
101  alumina,  2.0x60  silica  and  0.5x150  oxide  of  tin.  Some- 
times more  of  one  and  less  of  another  constituent  may  be  re- 
quired, but  generally  speaking  the  above  is  an  average  com- 
position. The  oxide  of  tin  makes  the  glazes  opaque  and  white. 
Any  color  desired  may  be  produced  by  adding  certain  metallic 
oxides,  for  instance,  oxide  of  cobalt  up  to  3  per  cent. ;  oxide 
of  copper  up  to  4  per  cent. ;  peroxide  of  manganese  up  to  8 
per  cent. ;  ferric  oxide  up  to  4  per  cent.  ;*  oxide  of  uranuim  up 
to  5  per  cent. ;  antimonate  of  lead  up  to  10  per  cent. 

The  above-mentioned  lead  glazes  comprise,  according  to 
their  composition,  a  scope  of  from  about  932°  F.,  dark-red 
heat,  to  2,100°  F.  (Seger's  cone  No.  i).  Above  these  tem- 
peratures lead  glazes  cannot  well  be  employed,  because  they 
possess  the  great  disadvantage  of  the  oxide  of  lead  readily 
volatilizing  under  the  influence  of  the  fire-gases,  whereby  the 
glazes  become  more  acid  and  refractory,  and  no  longer  turn 
out  bright.  The  longer  the  glazes  remain  in  the  fire  the  more 
apparent  this  evil  becomes,  and  the  stronger,  the  higher  the 
temperature  which  is  used.  The  glazes  containing  tin  fuse  at 
about  the  melting  heat  of  silver,  sometimes  above  and  some- 
times below  it,  according  to  their  composition. 


580  BRICK,  TILES   AND   TERRA-COTTA. 

The  most  important  glazes  for  roofing  tiles  are  those  free 
from  lead.  They  are  employed  in  the  form  of  clay  or  clay-like 
masses,  which  are  applied  to  the  tiles  and  then  burned  on.  It 
is,  however,  impossible  to  give  the  clays  such  a  composition 
that  the  glazes  fuse  at  an  early  period,  a  certain  degree  of 
heat  being  required  for  their  fusion.  A  glaze  of  O.2  equivalent 
potash,  0.8  lime,  0.3  alumina,  0.2  ferric  oxide  and  3.0  silica, 
fuses  at  about  2100  degrees  F.  (Seger's  cone  No.  i),  this 
being  the  lowest  fusing  point  for  such  glazes  which  can  be  at- 
tained ;  they  frequently  require  a  temperature  represented  by 
Seger's  cones  Nos.  6,  8,  and  sometimes  10.  The  glazes  which, 
at  least  for  low  temperatures,  must  always  contain  iron,  appear 
by  fusing  as  a  black  layer,  the  surface  of  which,  when  for  some 
time  exposed  to  atmospheric  influences,  acquires  a  brown  color, 
about  that  of  an  ordinary  pot  glaze.  By  heating  this  glaze  free 
from  lead  under  the  influence  of  reducing  gases,  the  ferric 
oxide  is  converted  into  ferrous  oxide,  and  the  layer  of  glaze 
appears  black.  By  adding  to  the  glaze  some  oxide  of  manga- 
nese, copper,  cobalt,  etc.,  it  also  acquires  a  black  color,  which 
is  permanent  and  does  not  assume  the  yellowish  coloration  of 
iron  glazes.  They  consist  of  ferrous  silicate,  corresponding  to 
finery  cinders.  They  are  produced  by  the  application  of  ferric 
oxide,  and  sand,  generally  inpure  ferric  oxide  (yellow  ochre) 
mixed  with  sand.  The  ferric  oxide  (ochre)  at  disposal  for  this 
purpose  always  contains  sand,  and  sometimes  more  sand  is  added. 
If  the  ferrous  silicate  is  burned  with  the  exclusion  of  reducing 
gases,  it  acquires  a  reddish  brown  color.  But  if  it  is  burned  in 
a  reducing  atmosphere,  it  becomes  pure  black,  and  the  surface 
then  assumes  a  slate-gray  color.  It  does  not  completely  fuse 
to  a  liquid  mass,  but  in  fact  only  frits  together.  The  glazes 
are  never  quite  bright  and  lustrous,  but  always  dull,  which  is 
however,  desirable.  According  to  its  composition  and  the 
proportion  of  ferrous  oxide  to  silica,  the  fusing  point  of  this 
glaze  may  be  as  high  as  that  represented  by  Seger's  cones 
Nos.  10  and  1 1,  or  as  low  as  that  represented  by  cone  No.  2. 

I  have  recently  occupied  myself  much  with  glazes,  and  have 


MANUFACTURE   AND   GLAZING   OF   ROOFING  TILES.       581 

found  that  their  higher  or  lower  fusing  points  are  chiefly  de- 
pendent on  their  content  of  silica.  The  glazes  richest  in  fer- 
rous oxide  are  by  no  means  the  most  readily  fusible.  The 
lowest  fusing  point  is  possessed  by  glazes  which  represent  a 
ferrous  bisilicate  (72  ferrous  oxide,  2x6o  silica),  the  refractori- 
ness increasing  with  an  increase  as  well  as  decrease  in  the  con- 
tent of  silica.  Somewhat  more  readily  fusible  than  the  pure 
ferrous  oxide  combinations,  are  those  which,  besides  ferrous 
oxide,  contain  manganous  oxide.  However,  even  such  a  glaze 
cannot  be  applied  to  a  tile  which  has  not  been  burned  at  at 
least  a  temperature  represented  by  Seger's  cone  No.  3.  Such 
mixtures  which,  besides  ferrous  bisilicate,  contain  considerable 
quantities  of  other  substances,  especially  alkalies,  lime  and 
alumina,  may  be  more  readily  fusible,  but  lose  thereby  their 
peculiar  character — the  slate-gray  color — and  are  converted 
into  glassy,  bright,  black  masses.  * 

It  is  certain  that  for  glazes  free  from  lead  the  fusing  point 
should  not  be  lower  than  Seger's  cone  No.  I  (2100  degrees  F.), 
and  for  those  containing  lead  not  higher  than  that  temperature. 
This  establishes  a  definite  boundary  between  these  two  kinds  of 
glazes,  which  cannot  be  passed.  Hence,  if  a  chemist  is  re- 
quired to  compose  a  glaze  free  from  lead,  or  furnish  a  receipt 
for  a  slate-gray  glaze  for  a  tile  which  cannot,  without  danger, 
be  heated  above  1832  degrees  F.,  it  will  be  impossible  for  him 
to  comply  with  the  demand. 

THE   MERRILL   ROOFING-TILE    MACHINE. 

The  practical  operation  of  the  Merrill  roofiing-tile  machine, 
shown  in  Figs.  237  to  248,  is  as  follows:  The  wheels  are  made 
to  revolve  in  direction  of  the  arrows ;  a  certain  portion  of  clay 
is  placed  in  the  dies  which,  by  the  corresponding  curvature  of 
their  faces,  when  the  dies  begin  to  move,  press  the  clay  at  one 
corner  or  end  by  a  rolling  motion,  thereby  packing  the  clay 
into  all  parts  of  the  dies,  and  forcing  the  surplus  clay  out  at  the 
opposite  corner.  While  the  clay  is  thus  being  pressed  the  nail- 
holes  are  punched,  the  punches  being  forced  out  by  the  head 


582 


BRICK,  TILES    AND   TERRA-COTTA. 


or  bar  coming  in  contact  at  the  proper  time  with  cam  A,  Fig, 
237,  indicated  by  the  dotted  lines,  attached  to  the  inside  of  the 
standards,  one  on  each  side  of  the  wheel,  over  which  the  pro- 
jecting ends  of  the  head  slide,  thereby  forcing  out  the  punches 
into  the  dies,  and  perforating  the  clay.  The  moment  that  the 
holes  are  punched  the  punches  are  withdrawn  into  the  wheel 


FIG.  237. 


FIG.  238. 


FIG.  241. 

by  the  springs.  At  this  time  the  tongue  at  the  bottom  of  the 
lower  die  is  forced  out  by  the  projecting  ends  of  the  head  H 
coming  in  contact  with  the  side  cams  B,  Fig.  237,  thereby 
forcing  outward  the  rod  d,  which  so  far  pushes  out  the  tongue 
as  to  allow  the  end  of  the  tile  thereon  to  fall  upon  the  endless 
apron  Nt  Fig.  237,  whereby  it  is  moved  away.  The  use  of  the 


MANUFACTURE   AND    GLAZING   OF   ROOFING  TILES.       583 


steam  in  connection  with  the  dies  is  to  heat  them  so  as  to  re- 
lieve the  clay  after  the  tile  receives  the  pressure. 
[  Fig.  237  is  a  side  elevation  of  the  machine.  Fig.  238  is  an 
end  elevation.  Fig.  239  is  a  plain  view.  Fig.  240  is  a  de- 
tached transverse  section.  Fig.  241  is  a  detached  vertical  sec- 
tion. Figs.  242,  243  and  244  are  detached  sections.  Figs.  245, 
246  and  247  are  views  of  a  tile  made  by  the  machine.  Fig. 
248  is  a  detached  section. 

The  construction  of  the  various  parts  of  the  machine  is  as 
follows : 

In  the  drawing,  Fig.  238  A  B  represent  a  pair  of  standards, 


FIG.  242. 


FIG.  243. 


FIG.  244. 


FIG.  245.  FIG.  246.  FIG.  247. 


FIG.  248. 


in  which  are  journaled  two  wheels,  CD,  which  engage  each  other 
by  the  gearing  E.  Under  each  of  the  dies  or  moulds  is  formed 
a  steam-chamber  0,  Fig.  241,  into  which  steam  is  admitted 
through  the  pipe  b.  One  end  of  this  pipe  terminates  in  one  of 
the  chambers,  and  the  opposite  end  terminates  in  the  hollow 
shaft  Gl  of  the  wheel,  into  which  steam  is  received  from  the 
boiler.  The  several  steam-chambers  are  connected  to  each 
other,  for  the  transmission  of  steam,  by  a  pipe  d,  Figs.  238  and 
239,  extending  around  the  wheel  from  one  chamber  to  another. 
The  purpose  of  this  chamber  will  presently  be  shown.  In  the 


584  BRICK,  TILES   AND   TERRA-COTTA. 

faces  of  the  wheels  referred  to  is  arranged  a  series  of  dies  or 
moulds,  FG,  which  are  so  constructed  as  to  give  the  desired 
shape  to  the  article  to  be  made,  which,  in  this  machine,  is  a 
roofing-tile.  Detached  views  thereof  are  shown  in  Figs.  245  and 
246,  which  give  a  view  of  both  sides  of  the  tile.  The  upper  and 
lower  dies  are  constructed  substantially  alike,  differing  only  in 
the'fact  that  in  the  bottom  of  each  of  the  lower  dies  is  placed  a 
metallic  plate  or  tongue  71,  of  the  same  form  as  the  inside  of 
the  die,  and  upon  which  the  clay  is  placed  and  prepared,  and 
whereby  the  pressed  article  is  forced  out  from  the  die  by  rais- 
ing the  tongue,  as  will  presently  be  shown.  The  tongue  re- 
ferred to  is  raised  out  of  the  lower  die  by  a  rod  </,  Fig.  241,  one 
end  of  which  is  secured  to  the  tongue, -whereas  the  opposite 
end  is  secured  to  a  bar  //,  Fig.  241.  The  two  ends  of  this  bar 
project  through  slots  c  in  the  arms  /  of  the  wheel,  in  which  the 
bars  slide  for  operating  the  tongues  of  the  dies.  J,  Fig.  241, 
is  a  spring  surrounding  the  rod  d  referred  to,  the  purpose  of 
which  is  to  retain  the  tongue  within  the  die.  Fig.  242  repre- 
sents an  enlarged  detached  view  of  one  of  the  dies,  the  face 
of  which,  and  also  the  face  of  the  tongue,  being  etched  or 
otherwise  made  with  a  roughened  surface,  so  as  to  confine 
small  portions  of  air  between  these  surfaces  and  the  clay, 
which  air,  when  the  pressure  is  removed,  will  expand  and  raise 
or  loosen  the  clay  from  the  roughened  surfaces.  Fig.  244  rep- 
resents detached  sections  of  the  upper  and  lower  dies,  with  their 
relation  to  each  other  while  pressing  the  clay  between  them ; 
and  Fig.  243  exhibits  a  longitudinal  section  of  a  die,  all  of 
which  shows  the  form  of  the  dies  for  making  the  tiles,  as  in 
Figs.  245  and  246.  In  the  upper  wheel  C,  there  is  an  arrange- 
ment similar  to  that  in  the  lower  wheel  for  ejecting  the  tile,  the 
purpose  of  which  is  to  punch  the  nail-holes  e  in  the  sides  of  the 
tile,  and  which  arrangement  consists  of  the  two  punches  K, 
Fig.  248,  attached  to  sliding  head  or  bar  /),  the  ends  of  which 
project  through  slots  of  the  arms  of  the  wheel. 


MANUFACTURE   AND    GLAZING   OF    ROOFING  TILES.        585 
MACHINE    FOR   MOULDING   ROOFING-TILE    FROM    PIASTIC   CLAY. 

The  machine  shown  in  Figs.  249  to  252  is  especially  de- 
signed for  the  formation  of  roofing-tile  from  plastic  clay. 

The  main  features  of  the  invention  consist  of  a  series  of  sim- 
ilar lower  dies  attached  to  a  revolving  horizontal  table,  and 
brought  successively  beneath  the  upper  dies ;  the  latter  consist 
of  two  parts,  viz.,  an  outer  shell,  which  forms  the  edge  of  the 
tile,  and  an  upper  die,  sliding  within  the  shell,  and  which  forms 
the  upper  surface  of  the  tile,  each  attached  to  suitable  slides, 
and  adapted  to  move  independently  with  a  vertical  reciprocat- 
ing motion.  In  combination  with  these  elements,  and  moved 
by  the  same  machinery,  is  also  an  automatic  feeding  apparatus. 

Figs.  249,  250  and  251  represent,  respectively,  a  side  eleva- 
tion, a  front  elevation,  and  a  plan  of  the  tile-machine ;  and  Fig. 
252  a  perspective  view  of  the  dies  and  shell  on  an  enlarged 
scale.  iL 

The  main  part  of  the  machine  is  attached  to  and  supported 
by  the  frame  A,  which  stands  upon  the  legs  B B.  Journaled 
in  the  upper  part  of  the  frame  is  the  shaft  C,  turned  by  the 
pulley  D.  On  the  front  of  this  frame  A  are  cast  or  attached 
suitable  guides  ee,  within  which  moves  the  slide  E,  carrying  on 
its  lower  end  the  upper  die  F,  and  moved  with  a  vertical  recip- 
rocating motion  by  the  cam  G.  Upon  the  outside  of  the  guides 
e  e  is  fitted  another  slide  H,  also  having  a  vertical  reciprocating 
motion,  moved  by  the  cam  /,  and  carrying  the  shell  J.  The 
lower  dies  K  K  are  attached  to  the  platform  Z,  which  is  keyed 
to  and  turned  by  the  shaft  M.  The  platform  L  rests  upon  an 
annular  bed  N,  attached  to  and  supported  by  the  frame  A,  and 
the  upper  surface  thereof,  being  planed  smoothly,  affords  a 
sliding  seat,  upon  which  the  platform  L  revolves. 

In  practice  it  will  be  found  convenient  to  have  both  the  an- 
nular bed  N  and  lower  die  F  cast  hollow,  and  charged  with 
steam,  when  in  use,  to  facilitate  the  separation  of  the  dies  from 
the  tile  after  the  latter  is  pressed.  Upon  the  shaft  C  is  an  ec- 
centric-cam 0)  connected  to  a  crank  on  one  end  of  the  shaft  Q 
by  the  rod  P ;  and  upon  the  opposite  end  of  the  shaft  Q  is  a 


586 


BRICK,  TILES    AND   TERRA-COTTA. 


crank-arm  5,  which  is   connected  by  a  rod  s  to,  and  moves  a 
loose  collar  T  on  the  shaft  M. 

This  collar  T  carries  a  pawl  t>  which  engages  the  ratchet  U 
on  the  shaft  M,  and  thereby  the  cam  0  causes,  at  each  return 
stroke  of  the  upper  die  F  and  shell  Jt  a  partial  revolution  of 


FIG.  250. 


FIG.  249. 


FIG.  251. 


FIG.  252. 


the  platform  L,  sufficient  to  bring  one  of  the  dies  K  in  position 
beneath  the  upper  die  and  shell. 

In    operation,  one  of    the  lower  dies  K  being   in    position 
beneath  the  upper  die,  with  a  portion  of  clay  thereon,  by  the 


MANUFACTURE   AND    GLAZING   OF   ROOFING  TILES.        587 

action  of  the  cams  /and  G,  the  shell  J  first  descends  and  sur- 
rounds the  die  K,  to  which  it  is  accurately  fitted.  The  upper 
die  then  descends  within  the  shell  and  presses  the  clay  into  the 
desired  shape,  all  excess  of  clay  escaping  through  the  holes  ii 
in  the  ends  of  the  shell  J.  The  upper  die  still  remaining  on 
the  clay,  the  shell  J  first  ascends ;  the  upper  die  F  then  as- 
cends ;  a  partial  revolution  of  the  platform  then  ensues,  and 
the  operation  is  repeated. 

Especial  attention  is  called  to  the  arrangement  of  the  lower 
die,  shell,  and  upper  die,  and  the  relative  motion  of  the  latter 
two  at  the  time  of  forming  the  tile.  The  upper  die  at  no  time 
entirely  leaves  the  interior  of  the  shell  J.  When  the  shell  J 
descends  upon  the  die  K,  the  three  parts  form  a  closed  mould, 
with  the  unpressed  clay  therein. 

By  causing  the  shell  J  to  rise  first,  it  cuts  off  two  streams  of 
surplus  clay  at  the  holes  i  i,  leaving  the  edges  of  the  tile 
smooth  and  clean  cut,  and  permits  the  upper  die  to  ascend 
without  tearing  the  green  tile,  which  could  not  be  done  if  the 
shell  J  remained  down. 

In  practice  it  is  found  that,  with  every  precaution  to  prevent 
it,  there  are  always  incorporated  in  the  pressed  tile  particles  of 
compressed  air,  which,  by  its  expansive  force,  would,  if  the  die 
F  remained  at  its  extreme  pressure  when  the  shell  J  was  re- 
moved, force  the  clay  out  laterally  between  the  upper  and  lower 
dies,  thereby  destroying  the  line  and  smoothness  of  the  edge  of 
the  tile.  This  is  avoided  by  using  an  eccentric-cam  G,  to 
operate  the  upper  die,  whereby  the  upper  die  begins  slowly  to 
ascend  the  instant  after  its  extreme  pressure,  thereby  permit- 
ting the  clay  to  expand  upward  by  the  time  the  shell  ascends 
above  it. 

Nail-holes  are  made  in  the  tile  as  follows :  Upon  the  shell 
J  are  two  standards  V  V,  the  upper  angle  whereof  is  so  high  as 
not  to  interfere  with  the  greatest  separation  of  the  upper  die 
and  shell.  Projecting  downward  from  the  top  of  these  are  pins 
c  cy  which  pass  through  holes  in  the  upper  die,  and  of  such 
length  that  their  lower  ends  shall  rest  against  the  face  of  the 


588  BRICK,  TILES   AND   TERRA-COTTA. 

lower  die  K  when  the  shell  J  is  at  its  extreme  downward 
stroke.  Their  operation  will  be  readily  understood  from  the 
foregoing  description  of  the  press  as  they  follow  the  motion  of 
the  shell  y. 

The  feeding  device  consists  of  a  hollow,  open  cylinder  W, 
supported  over  one  of  the  lower  dies  when  the  latter  is  at  rest, 
as  shown. 

Across  the  bottom  of  this  cylinder  slides  a  plate  X,  sup- 
ported by  an  arm  Y,  which'  swings  horizontally  on  the  shaft  M. 
In  this  plate  is  a  depression  d,  as  large  as  the  interior  circum- 
ference of  the  cylinder  W,  the  side  of  said  depression  toward 
the  centre  of  the  plate  being  open,  and  the  edge  of  the  plate  at 
that  opening  sharpened  to  form  a  knife.  This  plate  is  caused 
to  oscillate  across  the  lower  end  of  the  cylinder  W,  by  a  pitman 
attached  to  the  crank-arm  5. 

In  operation,  a  roll  of  tempered  clay  is  placed  in  the  cylinder. 
By  the  action  of  the  arm  S,  in  revolving  the  platform  L,  the 
depresssion  in  the  plate  X  is  brought  beneath  the  cylinder,  and 
into  this  the  roll  of  clay  settles,  when,  by  the  return  of  the 
plate,  a  slice  of  clay  is  cut  off,  and  falls  on  the  die  below. 

FIG.  253. 


Fig.  253  shows  the  common  form  of  tile-barrows,  which  are 
similar  to  the  brick-barrows,  with  the  exception  that  they  are 


MANUFACTURE   AND   GLAZING   OF   ROOFING  TILES.       589 

wider  at  the  front,  the  back  or  "  dash  "  is  higher,  and  the  wheel 
is  covered.     Fig.  254  shows  the  form  of  a  tile-truck  designed  to 

FIG.  254. 


carry  tiles  from  the  machine  to  the  drying-sheds ;  the  usual 
size  ot  the  platform  is  28x72  inches,  and  being  mounted  on  two' 
wheels  is  not  easily  upset. 


CHAPTER  XVII. 

THE   MANUFACTURE   OF  MOSAICS    AND    IMITATION   INLAID    OR 
INTARSIA   SURFACES. 

THIS  beautiful  method  of  cementing  various  kinds  of  stones, 
glass,  etc.,  seems  to  have  originated  in  Persia,  whence  it  found 
its  way  into  Greece  in  the  time  of  Alexander,  and  into  Rome 
about  170  B.  C.  The  critics  are  divided  as  to  the  origin  and 
reason  of  the  name.  Some  derive  it  from  mosaicum,  a  corrup- 
tion of  musaicum,  or,  as  it  was  called  among  the  Romans,  mu- 
sivum.  Scaliger  derives  it  from  the  Greek  Morisa,  and  imagines 
the  name  was  given  to  this  sort  of  work  by  reason  of  its  ingen- 
uity and  exquisite  delicacy.  Nebricensis  is  of  the  opinion  it 
was  so  called  because  "  ex  illis  picturis  ornabantur  musea." 
Mosaic  work  of  glass  is  used  principally  for  the  ornamentation 
and  decoration  of  sacred  edifices.  Some  of  the  finest  speci- 
mens of  this  work  are  to  be  seen  in  the  Church  of  the 
Invalides  at  Paris,  in  which  is  the  tomb  of  Napoleon  I.,  and  in 
the  fine  chapel  at  Versailles.  Mosaic  work  in  marble  is  used 
for  pavements  of  churches,  basilicas  and  palaces ;  and  in  the 
incrustation  and  veneering  of  the  walls  of  the  same  structures. 
As  for  that  of  precious  stones,  it  seems  to  be  used  only  for 
ornaments  for  altar  pieces  and  tables  for  rich  cabinets. 

The  mosaic  manufacture  at  the  present  day  in  Rome  is 
one  of  the  most  extensive  and  profitable  of  the  fine  arts. 
Workmen  are  constantly  employed  in  copying  paintings  for 
altar  pieces,  though  the  works  of  the  first  masters  are  fast 
moldering  away  on  the  walls  of  forgotten  churches.  The 
French,  at  Milan,  appear  to  have  set  the  example  by  copying 
in  mosaic  the  "Lord's  Supper"  of  Leonardo  da  Vinci;  but 
their  plan  was  to  do  much  for  Milan  and  nothing  for  Rome, 
and  consequently  a  great  many  invaluable  frescoes  of  Michael 

(590) 


MANUFACTURE   OF   MOSAICS.  591 

Angelo,  Raphael,  Domenichino  and  Guido  were  left  to  perish. 
It  takes  about  seven  or  eight  years  to  finish  a  mosaic  copy  of  a 
painting  of  the  ordinary  historical  size,  two  men  being  con- 
stantly occupied  in  the  work.  The  time  and  expense  are,  of 
course,  regulated  by  the  intricacy  of  the  subject  and  quantity 
of  the  work.  Raphael's  "  Transfiguration  "  took  nine  years  to 
complete,  ten  men  constantly  working  at  it. 

The  execution  of  some  of  the  latter's  work  is,  however,  con- 
sidered very  inferior.  The  slab  upon  which  the  mosaic  is  made 
is  generally  of  travertin  (ortiburtin)  stones,  connected  together 
by  iron  clamps.  Upon  the  surface  of  this  a  mastic,  or  cement- 
ing paste,  is  gradually  spread,  as  the  progress  of  the  work  re- 
quires it,  which  forms  the  adhesive  ground,  or  bed,  upon 
which  the  mosaic  is  laid.  The  mastic  is  composed  of  fine  lime 
from  burnt  marble,  and  finely  powdered  travertin  stone,  mixed 
to  the  consistence  of  a  paste  with  Ijnseed  oil,  Into  this  paste 
are  fixed  the  "  smalts,"  of  which  the  mosaic  picture  is  formed. 
They  are  a  mixed  species  of  opaque,  vitrified  glass,  partaking 
of  the  nature  of  stone  and  glass,  and  composed  of  a  variety  of 
minerals  and  materials,  colored  for  the  most  part  with  different 
metallic  oxides. 

Of  these,  no  fewer  than  1,700  different  shades  are  in  use. 
They  are  manufactured  in  Rome,  in  the  form  of  long  slender 
rods,  like  wires,  of  various  degrees  of  thickness,  and  are  cut 
into  pieces  of  the  requisite  sizes,  from  the  smallest  pin  point  to 
an  inch.  When  the  picture  is  completely  finished,  and  the 
cement  thoroughly  dried,  it  is  highly  polished.  Mosaic,  though 
an  ancient  art,  is  not  merely  a  revived,  but  an  improved  one. 
The  Romans  only  used  colored  marbles  at  first,  or  natural 
stones,  in  its  composition,  whfch  admitted  of  little  variety ;  but 
the  invention  of  "  smalts"  has  given  it  a  wider  range,  and  made 
the  imitation  of  painting  far  closer.  The  mosaic  work  at  Flor- 
ence is  totally  different  from  this,  being  merely  inlaying  in 
"  pietre  dure,"  or  natural  ornamental  or  precious  stones,  of 
every  variety,  which  form  beautiful  and  very  costly  imitations 
of  shells,  flowers,  figures,  etc.,  but  bears  no  similitude  to 
painting. 


592 


BRICK,  TILES   AND   TERRA-COTTA. 


Inventions  are  now  being  developed  by  which  mosaics  can 
be  cheaply  worked,  which,  of  course,  while  the  work  does  not 
compare  in  merit  to  that  of  Italy  and  Russia,  is  at  the  same 
time  suitable  for  many  purposes  of  domestic  ornamentation. 

The  contrivance  shown  in  Figs.  255  to  258  is  the  invention 
of  Mr.  Robert  Eltzner,  of  New  York  City,  and  is  for  the  manu- 
facture of  mosaic  plates  for  pavements,  wall  ornamentation, 


FIG.  256. 


FIG.  257. 


FIG.  258. 


furniture,  and  other  decorative  purposes  from  natural  and  arti- 
ficial material,  such  as  marble,  slate,  porcelain,  majolica,  glass, 
jet,  wood,  and  the  like,  so  that  any  desired  design  can  be  pro- 
duced without  the  employment  of  especially  skilled  hands,  and 
thus  very  ornamental  articles  be  furnished  at  reasonable  prices 
for  application  in  the  arts. 

The  invention  consists  of  a  mosaic  tablet  or  plate,  the  indi- 


MANUFACTURE   OF   MOSAICS.  593 

vidual  blocks  of  which  are  arranged  face  downward,  according 
to  a  pattern  or  design  on  transparent  paper  that  has  been 
placed  between  two  glass  plates,  so  that  light  can  fall  through 
from  below.  The  blocks  of  mosaic  which  form  the  plate  are 
finally  backed  by  means  of  a  cement,  leaving  open  joints, 
and  stiffened  with  and  exterior  strip  or  band,  as  will  appear 
more  fully  hereafter. 

Fig.  255  represents  a  perspective  view  of  the  table  on  which 
the  mosaic  plate  is  formed.  Fig.  256  is  a  detail  vertical  trans- 
verse section  of  the  same.  Fig.  257  is  a  detail  side  view  of  a 
portion  of  the  table,  both  figures  being  drawn  on  an  enlarged 
scale,  and  Fig.  258  is  a  plan  view  of  a  mosaic  plate  formed  on  a 
table. 

In  carrying  out  the  invention,  a  table  A,  of  the  size  of  the 
mosaic  plate  to  be  formed,  is  supported  on  a  suitable  stand  B. 
The  table  A  is  made  of  an  exterior  iron  frame  A1,  and  of  two 
glass  plates  a  and  b,  between  which  is  placed  the  drawing  of 
the  design  which  is  to  be  produced  in  mosaic.  The  design  is 
made  on  transparent  or  translucent  tracing-paper,  which  is 
placed  between  the  two  glass  plates  with  the  face  side  down- 
ward, and  secured  by  gum  to  the  lower  glass  plate  b.  The 
thickness  of  the  covering  glass  plate  a  increases  with  the  size, 
weight,  and  thickness  of  the  mosaic  tablet  to  be  produced. 
Upon  the  top  glass  plate  a,  a  rectangular  frame  of  upright  glass 
strips  c  is  placed,  the  corners  of  which  are  held  together  by 
stout  paper  strips  pasted  thereto.  Below  the  glass  strips  c  is 
placed  a  layer  of  paper,  which  covers  the  glass  plate  a  outside 
of  the  glass  strips  c,  so  as  to  protect  the  surface  of  the  former. 
Outside  of  the  vertical  glass  strips  c  are  arranged  flat  rubber 
strips  d,  also  intermediate  rubber  strips  dl,  d'1  between  the  glass 
plates  a  b  and  frame  A  l,  the  rubber  strips  d*,  d2,  and  the  clamps 
e,  which  are  applied  near  the  corners  of  the  frame  A  l,  holding 
the  glass  plates  firmly  in  position  upon  the  iron  frame  of  the 
table.  The  vertical  glass  strips  c  vary  in  height  according  to 
the  thickness  of  the  mosaic  plates  to  be  formed,  and  serve  as 
the  exterior  walls  for  the  cement  backing  which  is  given  to  the 

38 


594  BRICK,  TILES   AND   TERRA-COTTA. 

mosaic  plate.  A  strip  or  band  f,  of  galvanized  wire-gauze,  is 
placed  in  position  along  the  inner  surface  of  the  glass  strips,  as 
shown  in  dotted  lines  in  Fig.  256.  The  band  f  should  not  ex- 
tend lower  down  than  the  depth  of  the  joint  between  the  blocks 
of  the  plates,  for  which  purpose,  so  as  to  obtain  the  correct 
position  of  the  band  f,  a  flanged  zinc  strip/1  is  placed  upon 
the  glass  plate  a,  below  the  rubber  strips  d,  the  zinc  strips  ex- 
tending below  the  glass  strips  c  c  to  the  inside,  its  flange  pro- 
jecting upward  along  their  inner  surface  for  supporting  the 
band  /,  as  shown  in  Fig.  256.  The  individual  blocks  of  mosaic, 
whatever  be  the  material  employed,  are  now  placed  in  position 
upon  the  covering  glass  plate  a,  according  to  the  design  repre- 
sented on  the  tracing-paper  between  the  plates  b  a.  As  the 
light  passes  through  the  glass  plates  from  below,  it  renders  the 
configuration  and  colors  of  the  design  clearly  visible,  so  that 
the  exact  position  and  color  of  the  blocks  required  are  clearly 
recognized.  One  row  after  the  other,  from  the  left  to  the  right, 
is  successively  placed  in  position,  the  faces  of  the  blocks  being 
gummed,  so  that  they  adhere  to  the  glass  plate.  If  it  be  de- 
sired to  bring  out  some  portions  of  the  design  in  relief,  the 
remaining  portions  have  to  be  covered  with  square  glass  plates 
of  the  size  of  the  block,  so  that  the  blocks  placed  thereon  are 
set  somewhat  below  the  blocks  without  glass  plates.  When  all 
the  blocks  are  placed  in  position  according  to  the  design,  the 
covering  plate  a,  with  the  blocks  remaining  thereon,  face  down- 
wards, is  removed  from  the  frame  for  being  backed  and  finished, 
while  the  table  itself  is  ready  for  forming  the  next  mosaic  plate. 
For  finishing  the  mosaic  plate,  the  open  joints  between  the 
blocks  are  now  partly  filled  up  with  a  layer  of  fine  sand  to  the 
depth  of  the  joints.  As  soon  as  this  is  done,  a  backing  g\  of  a 
proper  cement,  plaster-of-paris,  or  other  suitable  material,  is 
spread  into  the  joints  and  over  the  back  of  the  blocks  until 
they  are  covered  to  the  thickness  of  one-eighth  to  one-quarter 
of  an  inch.  A  layer  gl  of  wire-gauze  is  placed  upon  the  cement 
and  imbedded  therein,  after  which  it  is  covered  with  a  thick 
layer  of  cement,  plaster-of-paris,  or  other  material,  to  which, 


MANUFACTURE   OF   MOSAICS.  595 

according  to  the  thickness  of  the  plate,  sand  or  small  lumps  of 
stone  are  added.  As  soon  as  the  cement  backing  has  suffi- 
ciently set,  the  clamping-screws  are  unscrewed,  the  paper  strips 
at  the  corners  of  the  glass  strips  c  cut  through,  and  the  latter 
removed.  The  mosaic  plate  is  then  lifted  off  from  the  glass 
plate  a,  and  placed  face  upward  on  a  suitable  setting-plate  for 
final  drying.  The  joints  are  then  cleared  of  the  adhering  sand 
by  means  of  a  brush,  and  the  mosaic  plate  is  finished. 

If  desired,  the  blocks  may  be  connected  in  a  still  more  re- 
liable manner  by  means  of  short  metallic  strips,  which  are  cast 
in  by  the  cement  between  the  blocks,  or  by  other  means,  as 
wished.  In  this  connection  it  may  be  mentioned  that  the  proper 
size  of  the  working-table  to  be  used  is  preferably  equal  to  four 
square  feet,  so  that  four  mosaic  plates  each  one  square  foot  in 
size  may  be  made  at  the  same  time,  the  separation  of  the  plates 
being  readily  obtained  by  means  \oi  a  dividing-cross  of  glass 
strips.  If  larger  mosaic  plates  are  desired,  larger  working- 
tables  may  be  used.  The  frame  of  the  table  is  preferably  con- 
nected to  the  supporting  stand  by  means  of  a  hinged  joint  and 
semicircular  guide-rails,  so  as  to  be  set  into  into  inclined  posi- 
tion, by  which  the  passage  of  the  light  through  the  design  is 
facilitated.  If  extra  large  and  heavy  mosaic  plates  h  are  to  be 
made,  the  lower  glass  plate  b  is  made  of  several  pieces,  between 
which  iron  stiff ening-rails  are  interposed. 

The  advantages  of  this  improved  method  of  manufacturing 
mosaic  plates  are  that  any  desired  design  may  be  quickly  pro- 
duced without  the  employment  of  skilled  hands,  and  that  a 
number  of  persons  can  be  employed  at  the  same  time  to  pro- 
duce different  plates.  The  plates  can  be  made  by  daylight  or 
artificial  light,  provided  the  colors  on  the  design  can  be  prop- 
erly distinguished.  As  the  joints  between  the  blocks  are  open, 
a  secure  foothold  is  furnished  when  used  for  pavements.  The 
plates  do  not  require  to  be  made  of  any  great  thickness,  as  the 
inclosing  band  and  interposed  layer  of  wire  gauze  in  the  back- 
ing impart  to  them  considerable  strength  and  thickness. 


596  BRICK,  TILES    AND   TERRA-COTTA. 

IMITATION    INLAID    OR    INTARSIA   SURFACES. 

The  invention  shown  in  Figs.  259  to  261  relates  to  the  pro- 
duction, as  distinctve  articles  of  manufacture,  of  tiles,  table- 
tops,  wainscoting,  panels,  work-boxes,  articles  of  furniture  of 
all  kinds,  and  fancy  or  ornamental  articles  generally. 

A  mould  or  matrix  is  first  prepared,  of  metal,  slate,  or  any 
fit  material,  and  of  suitable  size  and  construction,  in  the  bottom 
of  which,  or  in  the  bottom  and  sides  of  which,  the  outlines  of 
the  ornament  or  ornaments  with  which  the  finished  article  is  to 
be  embellished  are  depressed,  sunk,  engraved,  or  intagliated. 
Into  the  mould  or  matrix  thus  prepared  is  placed  the  material, 
compound,  or  composition  which  is  to  form  the  base  of  the 
manufactured  article.  If  this  is  to  be  an  ornamental  plaque  or 
a  tile,  for  example,  clay,  plaster-of-paris,  or  any  artificial  stone 
compound  may  be  used,  which  is  pressed  into  the  mould,  so 
that  the  intagliated  lines  in  this  will  appear  upon  the  plaque  or 
tile,  when  this  is  withdrawn  from  the  mould,  as  outlines  of  relief. 

Almost  any  material,  compound,  or  composition  is  capable 
of  being  used  with  and  ornamented  by  this  process,  such  as 
plastic  materials  or  compounds,  stone,  wood,  cast  metal,  or  any 
sheet  metal  or  metallic  foil,  such  materials  as  are  not  themselves 
capable,  on  account  of  hardness,  of  receiving  an  impression  in 
the  mould  or  matrix  being  first  covered  or  coated  with  a  com- 
pound of  a  soft  or  plastic  nature.  Wood,  by  being  steamed, 
boiled,  or  treated  in  several  other  well-known  ways,  is  adapted 
for  ornamentation  by  this  process,  either  plain  or  veneered,  and 
with  or  without  a  plastic  coating  of  varnish,  shellac,  or  any  suit- 
able paint  composition. 

Fig.  259  is  a  plain  view  of  a  plaque  or  panel  with  an  imita- 
tion-intarsia  surface.  Fig.  260  is  a  section  of  the  mould  or 
matrix;  and  Fig.  261  is  a  similar  section,  showing  a  modifica- 
tion in  the  construction  of  the  mould  or  matrix. 

In  the  treatment  of  some  materials  it  is  desirable  to  construct 
the  matrix  in  the  shape  of  rollers,  one  of  which  has  a  flat  sur- 
face, and  the  other  is  provided  with  indented  or  engraved  lines, 
which  will  form  the  outlines  in  relief  upon  the  material  passed 


MANUFACTURE   OF   MOSAICS. 


597 


between  them.  When  a  hollow  mould  or  matrix  is  used,  this 
may  be  constructed  as  represented  in  Fig.  261,  that  is,  with  a 
raised  or  depressed  part  ay  forming  either  a  shoulder,  as  indi- 
cated by  the  full  line,  or  a  recess  as  indicated  by  the  dotted 
lines,  at  each  end  of  said  figure,  which  shoulder  or  recess,  as  the 
case  may  be,  surrounds  the  engraved  or  intagliated  bed  of  the 
mould,  by  which  the  ground  or  real  surface  of  the  article  or 
material  to  be  ornamented  will  be  exposed  in  its  natural  state. 
By  either  of  these  methods  a  base  may  be  used,  which  consists 

FIG.  259. 


FIG.  260. 


j!jaSgiSSg^^ 


-".-; 1 


FIG.  261. 

of  several  parts  or  layers,  which  allows  of  an  endless  combi- 
nation and  variety  of  materials  adapted  to  be  used  by  this 
process  in  the  production  of  imitation-intarsia  articles  of  man- 
ufacture, or  articles  of  any  kind  ornamented  by  this  process. 

After  the  base  has  been  produced  with  lines  in  relief  in  the 
manner  described,  and  the  spaces  within  the  lines  filled  in  with 
enamel,  paint,  or  any  suitable  colored  composition,  and  the  sur- 
face rubbed  down  smooth,  and  varnished,  if  desired,  as  fully  set 


598  BRICK,  TILES   AND   TERRA-COTTA. 

forth,  the  article  so  prepared,  if  of  clay,  and  ornamented  with 
mineral  colors  or  enamel,  is  baked  to  give  it  the  requisite  de- 
gree of  hardness  and  durability,  and  bring  out  the  colors.  The 
subsequent  treatment  of  the  ornamented  articles  will,  of  course, 
differ  according  to  their  nature  and  the  purposes  for  which 
they  are  intended ;  but  the  process  of  producing  the  raised 
outlines  and  subsequent  filling  in  with  coloring  matter,  is  in 
all  cases  substantially  the  same. 


INDEX. 


A  BOO  ROASH,  pyramid  of,  5 
Acids,  treatment  of  clays  with, 

364 
Acme  machine,  die  of  the,  139 

improved,  145-147 

Adams,  Nathaniel,  brick  machine  in- 
vented by,  20 
Thos.   F.,  permanent   kiln   roof 

invented  by,  303-305 
Adenne,  Belgium,  drying  of  large  re- 
fractory pieces  at,  381 
Adobe  houses,  10 
Adobes,  4 

Assyrian,  6 
Babylonish,  5 

construction  of  pyramids  of,  5 
manufacture  of,  10 
store-houses  of,  5 
use  of,  in  various  countries,  9,  10 
Aiken,  H.,  ring-pit  invented  by,  111- 

114 

Akron  Fire  Brick  Works,  Akron,  O., 
steam  dry  floor  used  by  the,  351 
process  and  river  process  of  mak- 
ing sewer  pipe,  difference  in 
the,  426,  427 

of  making  sewer  pipe,  425 
sewer-pipe,  character  of,  431 

reason  for   the  popularity 

of,  430 

works,  device  for  making 
curves,  elbows,  etc. , 
used  by  the,  431,432 
inability  of,  to  make 
Cincinnati  Standard 
pipe,  431 

worst  trouble  of,  430 
Albite,  32 

Alhambra   Palace,    enameled    brick- 
work of  the,  402 
Alkalies,  withdrawal  of,  by  cyanogen, 

323,  324 

Alligator  jaws,  495 
Alumina  and  silica,  relation  between,  I 

54 

hydrated  silicates  of,  54 
Amboy  clay  of  N.  J.,  47 


America,  cost  of  burning  1000  brick 

in,  294 
coal  in,  294 

market  price  of  brick  in,  294 
methods  of  grinding  fire-clay  in, 

372-375 

rapid  advancement  of,  in  the  pro- 
duction of  tiles,  522 
American  brick,  volume  of,  294 
clays  for  glass  pots,  395,  396 
Amsterdam,  city  hall  of,  14,  15 
Analyses  of  fire-clays  and  associated 
refractory  materials,  tables  of,  68-76 
Analysis,    method   of,  for  fire-clays, 
feldspars,     kaolin,     and     fire- 
sands,  78-80 
of  clay,  necessity  of,  58 
Anglo-Saxons,  buildings  of  the,  12 
Annealing  furnace  for  glass  pots,  398 
paving-brick,  228-230 

principle  involved  in,  229, 230 
Arch  brick,  blackening  of  the  faces 

of,  336 
Arch  of  Constantine,  12 

tile  for  door  of  furnace,  334 
Architects,  ideas  of,  in  regard  to  terra- 
cotta, 479 

Architectural    terra-cotta,     manufac- 
ture of,  468-510 
Architecture,  Babylonish,  decoration 

in,  5 

mediaeval,  ecclesiastical  and  pa- 
latial, of  Italy,  13,  14 
Art-tile  soda  fountains,  specimens  of, 

521 

works  in  the  United  States,  522 
Ashes,  abrasive  and  corrosive  power 

of,  307 

Assyria,  designs  in  tiles  in,  516 
drying  of  brick  in,  7 
enameling  brick  practiced  in,  402 
manufacture  of  brick  in,  6,  7 
plains  of,  6 

tile-incrusted  buildings  of,  517 
Assyrian  buildings,  exploration  of,  7,8 
edifices,  6 
tablets,  511 


(599) 


6oo 


INDEX. 


Assyrians,  glazed  tiles  of  the,  515,516 
profuseness  of    color    employed 

by  the,  542 

Atchison,  Kans.,  burning  street  pav- 
ing-brick at,  223,  224 
clay  at,  42 
manufacture  of  paving-brick 

at,  230 
Automatic  wire  cut-off,  Chambers,  205 

BABElv,  tower  of,  2,  450 
burnt  brick  used  in  the,  11 
Babylon,  decorated  brick  of  the  walls 

of,  403 

enameling  brick,  practiced  in,  402 
use  of  brick  in  the  walls  of,  4 

tiles  as  a  circulating  me- 
dium in,  517,  518 
Babylonians,  glazed  tiles  of  the,  515, 

516 
Babylonish   architecture,    decoration 

in,  5 
brick,  colors  of,  4,  5 

sizes  of,  5 

Bagdad,  ancient  brick  in  the  walls  of,  4 
Baltimore,  first  pressed  brick   made 

in,  256 

tile  works  in,  560 
Banks,  clay,  strengthening  the  walls 

of,  64 

Barnhart  steam-shovel,  118,  119 
Barrow  for  roofing  tiles,  588,  589 

sewer- pipe  and  drain-pipe, 444 
Batley,  Mr.,  on  the  use  of  pulverized 

brick  and  grog,  281 
Beatrice,  Neb.,  burning  paving-brick 

at,  224 
Beattie,  Mr.,  on  the  manufacture  of 

paving-brick,  230,  231 
Belgian  clay,  cementing  capacity  of, 

367 
Belgium,  material  used  in,  for  blast 

furnace  brick,  310 
mixing  fire  clays  in,  368 
Benches,  packing  the  brick  in  the,  169 

setting  of,  170,  171 
Benezet  brick,  339 
Bessemer  converter  tuyere,  334 
Bible  face,  92 

Birs,  Nimrod,  mounds  of  brick  at,  4 
Bischoff,  Dr.  Carl,  assay  of,  of  clay,  58 
formula  of,   for  the 
calculations  in  get- 
ting at  the  value  of 
a  fire-clay,  50 
Biscuit,  418 

brick  process,  424 
Bitumen,  brick  laid  in,  5 


Bituminous  coal,  number  of  pounds 
of,  equal  to  one  cord  of  wood, 
179,  182 

matter  in  clay,  26 
Blake  crusher,  495 
Blashfield,  Mr.,  terra-cotta  of,  80 
Blast  furnace  bosh,  317 

bottom  blocks,  338 

bottoms,  318 

brick,  material   used  for,  in 

Belgium,  310 
crucible  and  bosh,  337 
cyanide  of  potash  on  the  walls 

of,  324 

difficulties  of  procuring  a  re- 
fractory  material   for    the 
brick  work  of  a,  316 
dissolving  influences  of  the, 

upon  the  brickwork,  316 
diversity  of  objects  it  has  to 

serve,  313 

gases,  cyanogen  in,  321,  322 
linings,  317,  318,  336 
furnaces,  best  means  of  preserv- 
ing the  walls  of,  319 
.  causes  of  the  rapid  wear  of 
the  brickwork  of  the  stacks 
of,  321 
refractory  brickwork  of,  and 

its  preservation,  313-326 
salts  soluble   in  water  con- 
tained  in    cokes   used    in, 
324-326 
term  refractory  as  applied  to 

brick  in  regard  to,  316 
Blasting,  64 
Blocks  and  tiles,  machine  for  making, 

344,  345 

necessary  in  setting 
a  bench  of  fire  clay 
retorts  in  gas 
works,  343 

drying  and  tempering  of,  380 
large,  defect  in  making,  343,  344 
tiles   and   special   pieces,   manu- 
facture of,  336-345 
Blue  covering  mass,  575 

-green  stain,  recipe  for,  414 
Ridge,  Mo.,  clay,  395 
Bobbing  the  brick,  92 
Bodies,  weight  of,  417 
Body,  first,  for  enameled  brick,  415 

white,  424 

Boice,  J.  R.,  introduction  by,  of  the 
use    of    natural    gas    for    burning 
brick  in  Toledo,  190 
Boiler  tiles,  339 
Bond  clay,  59-61 


INDEX. 


60 1 


Boston,  annual  consumption  of  brick  j 

in,  20 
bricks  not  much  used  in,  in  early  j 

times,  17 
erection    of    the    first     "Towne 

House"  in,  17 
"Old  State  House" 

in,  17,  18 

first  Episcopal  church  in,  18 
muffle  terra-cotta  kilns  used  in, 

503,  504 

"Triangular  Warehouse  "  in,  18 
Bottom-dumping  clay  car,  124,  125 
Brewer  machine,  494 
Brick,  advantage  of  coloring  with  a 

lively  heat,  185 

advice  to  one  about  to  undertake 
the  making  of,  by  the  dry  pro- 
cess, 240,  241 
American,  superiority  of,  19 

volume  of,  294 
ancient  and  modern,  of  Egypt,  4 

in  the  wall  of  Bagdad,  4 
and   terra-cotta   structure,   ideal,  | 

482 
tile,  coke  oven,  325 

elevating  devices  for,  455 
machine,  improved 'Cen-  j 
teunial,  with  new  pat- 
tern  side-cut  delivery 
table,  143-145 
Siemens  regenerator,  322 
annual  consumption   of,    in   the 
leading    cities   of    the    United 
States,  20 

artificial   drying   of,  general  ad- 
vantages of,  151,  152 
Babylonish,  colors  of,  4,  5 

sizes  of,  5 
bobbing  the,  92 

building,  earliest  in  England,  13 
first,  in  the  United  States,  15 
burning,  various  methods  of,  101 
cars  used  for  setting,  172-175 
classification  of  methods  of  dry- 
ing, 150 

clays,  Hudson  river,  36,  37 
color  of,  30,  31 
common      building,      absorbent 

power  of,  221 
cost  of  burning,  in  the  Hoffman 

kiln,  183 
in  Trenton,  N.J., 

268 

t  loco,    in    Amer- 

ica, 294 
in     Europe, 
294 


Brick,  crushed,  mixing  clays  with,  449 
cupola  lining,  336 
days   to    "strike    out,"    for    re- 
pressing, 268,  269 
die,  Niedergesaess  patent  lubri- 
cating, 139-141 
dies  of  various  machines,  139 
discoloration  of,  in  the  kiln,  186 
disintegration  of,  137 
dry-clay,  manufacture  of,  235-250 
drying  of,   by  a  current  of  hot 

air,  166 
by  the  pallet  system,  151, 

156,  157 
in  sheds,  advantages  of, 

151 

in    the    sun,    disadvant- 
ages of,  150,  151 
with  exhaust  steam  from 

the  engine,  158-161 
shed,  improved,  153-156 
early  employment  of,  2 
effect  on,  of  limestone  and  lime- 
pebbles  in  the  clay,  33 
Egyptian,    stamped    with    prae- 
s      nomens  and    names    of  mon- 

archs,  7 

enameled,  cooling  of,  after  burn- 
ing, 422,  423 

defects  engendered  in,  421 
dips  for,  415 

firing  of,  416,  417,  421,  422 
first  body  for,  415 
history  of,  402 
manufacture  of,  402-424 
preparation     of    stains    for, 

418,  419 

secrecy  maintained  by  the 
manufacturers  of,  in  Eng- 
land, 404,  405 

setting  of,   in  the  kiln,  416, 

419,  420 

stains  for,  414,  415 
enameling,  instructions  for,  416, 

417 

explanations  of,  417-419 
of,  412-419 
English,    volume    and    size    of, 

294 
fine  front,  directions  for  making, 

254.  255 

soaking  the  clay  for,  126 
first   attempt    to    burn    continu- 
ously, 291 

burned  in  kilns  by  the  Ro- 
mans, 11 

front,  preserving  the  faces  of,  275 
German,  volume  and  size  of,  294 


602 


INDEX. 


Brick,  glass  furnace,  322 

green,   setting  the,   in   the  kiln, 

95-97 

hacking  the,  93 

hand-made,  amount  of  coal   re- 
quired to  burn  a  kiln  of,  101 
burning  of,  97-101 
making  and  burning  a  kiln 

of,  87-114 

tools  and  appliances,  used  in 
the  manufacture  of,  101-103 
history  of,  1-25 

impossibility  of  burning  all  the 
yearly  product  of,  with  wood, 
182 
invested  capital  represented  by  a 

kiln  of,  ready  to  fire,  273 
laid  in  bitumen,  5 
laminations  of,  138 
layers'  labor,  price  of,  in  1705,  in 

Philadelphia,  16 
wages  of,    in    1630,   in   New 

England,  15 
machine,  Chambers,  200-208 

invented  by   Nathaniel   Ad- 1 

ams,  in  1835,  20 
-made,    partially   drying    of, 

for  re-pressing,  152 
which  are  to  be  enameled, 
trouble  with,  407,  408 
machines,  but  little  attention  paid 
to    the     improvement    of,  | 
until  1835,  19 
classification  of,  116,  117 
dry-clay,  243,  244 

drawbacks  to,  243 
lack    of  knowledge    by 
those  having  charge  of  i 
them,  243,  244 
strength  of,  243 
early,  19 
revolution  by,  in  brickmak- 

ing,  24 
used  in  making  the  glut  for 

pressed  brick,  261,  262 
makers,  earliest  record  of,  in  the 

United  States,  15,  16 
making  by  machinery,  divisions  | 

of  the  process  of,  117 
corner-stones     of     financial 

success  in,  115 
decline  in,  12 

floor,  heating  and  construc- 
tion of  a,  408-411 
illustrations  of,  on  the  tombs 

of  Thebes,  3 
in  the  South.  20,  21 
Nile  mud  for,  4 


Brick,  making,  perfection  in  the  art 

of,  by  the  ancients,  9 
progress  of,  2 

revolution  in,  by  brick  ma- 
chines, 24 
safe  and  reliable  basis  of,  as 

regards  machinery,  116 
manufacture  of,  by  the  Romans  in 
Germany  and  England,  12 
in  Assyria,  6-7 
market  for,  115 

price  of,  in  America,  294 

in  Europe,  294 
Milwaukee  cream-colored,  31 
mounds  of,  at  Birs  Nimrod,  4 
New  York,  volume  of,  294 
ornamental,  277-283 
pavements,  present  boom  in,  22 
pressed,  251-277 

and  ornamental,  manufacture 

of,  251-283 
setting  of,  in  the  kiln,  171, 

252,  253 

press,  semi-plastic,  249,  250 
pressure  required  to  repress  a,  271 
pulverized  or  grog,  use  of,  281 
quality  of,  in  the  first  century  of 

the  Christian  era,  11-12 
refractory,  abrasion  of,  321 

destruction  of,  by  carbon,  326 
removing  the,  from  the  kiln,  274 
requirements  of  the  business  of 

manufacturing,  23-24 
revolution  in  the  mode  of  manu- 
facturing, 20 
semi-plastic,  248-250 
setting  the,  in  the  kiln,  169-172 
soft,  production  of  in  continuous 

kilns,  292 
Spiegel  cupola,  336 
stiff-clay,  moulding  of,  137-139 
street-paving,     manufacture     of, 

209-234 

problem  to  be  solved  in 
the  production  of,  38 
sun-dried,  inefficiency  of,  to  with- 
stand the  action  of  water,  8 
use  of  in  various  countries, 

9,10 

taxation  of,  in  England,  14 
tempered  clay,  manufacture    of, 
includiag  description   of  most 
modern  machinery,  115-199 
term  refractory  as  applied  to,  in 

regard  to  blast  furnaces,  316 
triangular,  5 
truck,  178 
turning  up  the,  92 


INDEX. 


603 


Brick,  unburned,  or  teba,  7 

use  of,  in  Mesopotamia,  8,  9 
used  in  the  great  wall  of  China,  9  | 
use  of,  in  the  walls  of  Babylon,  4 
value  of  clay  when  manufactured 

into,  493 

very  hard  and  durable,  23 
vital  importance  of  proper  burn- 
ing of,  264 

walls,  ventilating  tunnels  in,  8 
washed,  93 
wedge-shaped,  5 

which  are  to  be  enameled,  press- 
ing of,  411,412 
which  is  to  be  enameled,  making 

of,  407,  408 

work  of  a  blast-furnace,  difficul- 
ties of  procuring  a  refrac- 
tory material  for  the,  316 
of  the  stacks  of  blast-furnaces, 
causes   of  the   rapid  wear 
of,  321 
refractory,  of  blast-furnaces, 

and  its  preservation, 3 13, 326  f 
British  silica  fire-brick,  386 
Britton,  J.  Blodgett,  analysis  of  Far- 

randsville,  Pa.,  fire-clay  by,  48 
Bronguiart,    formulae    by   for  glazes 

free  from  lead,  529 
Brose  Patent  Tile  Table,  463,  464 
Brown  covering  mass,  575 

G.  H.,  on  burning  paving-brick, 

224,  225 

on  the  moulding  and  press- 
ing of  paving-brick,  219-221 
on  the  preparation   of  clay 

for  paving-brick,  218 
stains,  recipes  for,  414 
Brush,  Wm.  H  ,  improvement  in  tem- 
porary kilns  by,  284-287 
on     starting     and     managing    a 

paving-brick  plant,  212 
Bucyrus  Brick  and  Terra-Cotta  Co., 
analyses  of  shale  clay  used  by,  44 
Bucyrns  drier,  166-169 

giant  machine,  special,  147-149 
side-cut  automatic  table,  149 
Buff  body,  improvement  in  the,  417 

recipe  for,  413 
Building-brick  clays,  30-36 

common,       absorbent 

power  of,  221 
common  hard,  differ- 
ence in  the  cost  of 
burning  of,  and  pav- 
ing-brick, 223 
common,  market  for, 
115, 116 


Building-brick,  mining  clay  for,  117- 

120 
selecting  clays  for,  34- 

36 

Buildings,  designs  of,  in  which  terra- 
cotta is  used,  479 
disfigurement  of,  481 
tile-encrusted,  of  Assyria,  517 
use  of  terra- co tta  in  the  construc- 
tion of,  481 
Bur  mill,  494 

Burning  and  making  a  kiln  of  hand- 
made brick,  87-114 
bad,  due  to  careless  setting,  169 
brick,  178,  179 

comparative  cost  of,  with  oil 

and  other  fuels,  195-197 
cost  of,  in  Trenton,  N.  J.,  268 
recent  progress  in,  182-186 
various  methods  of,  101 
with  crude  oil,  191-199 
with  natural  gas,  186-191 
drain  tile,  457-461 
dry  clay  brick,  245-248 
v  fire-brick,  383,  384 

chemical  changes  in,  311, 312 
fuel  for,  274 
importance  of  careful  study  and 

improvements  in,  264 
paving-brick,  222-230 
pressed-brick,  263-265,273,  274 
proper,  vital  importance  of,  264 
quick,  reasons  for,  266 
roofing  tiles,  550,  551 
silica  brick,  390,  391 
terra-cotta,  502-505 
tile  with  crude  oil,  191-199 
time  required  in,  274 
Burnt  platting,  98 

CALCINING,  364-366 
\j     kilns,  365,  366,  384-386 
California,  brickmaking  in,  21 
stucco  or  enamel  used  in,  9 
use  of  adobes  in,  9 
Calkins,  J.  H.,  on  the  production  of 

paving-brick,  38 
Cambria  Iron   Co.,  Johnstown,   Pa., 

shale  from  the  mines  of  the,  45 
Camp,  Horace  B.,  machine  for  form- 
ing sockets  on  curved  earthen- 
ware pipes  invented  by,  437-440 
machine     for     making     curved 
earthenware     pipes,    invented 
by,  435-437 

Carbonaceous  matter  in  clay,  26 
Carbonates,  alkaline,  effect  of,  upon 
clay,  29 


604 


INDEX. 


Carbon  brick,  destruction  of,  319 
properties  of,  326 
resistance  of,  to  the  dissolv-  | 

ing  action  of  clay,  318 
deposits  in  fire-brick,  326-330 
destruction  by,  of  refractory 

brick,  326 
fire-brick  for  furnaces,  394,  395 

glass  pots,  gas  re- ; 
torts,  silica  fire- 
brick   and    fire- 
brick,  manufac- 
ture of,  306-401 
method  of  setting,  395 
Carnell,  Geo.,  directions  by,  for  mak- 
ing fine  front  brick,  254,  255 
Carpenter,  R.  C.,  on  the  construction 

of  steam  works  for  driers,  158-161 
Carpenters,  wages  of,  in  1630,  in  New 

England,  15 

Cars  used  in  handling  brick  for  set- 
ting, 172-175 

Celadon  stain,  recipe  for,  414 
Cement,  47 

or  chamotte,  364 
Centennial  machine,  die  of  the,  139 

tile-making  machine,  461-4^3 
Chaldea,  drying  of  brick  in,  7 

enameling  brick  practiced  in,  402  I 
tiles  of,  516 

Chaldean  buildings,  ventilating  tun- 
nels in  the  brick  walls  of,  8 
tablets,  511 

Chambers  brick  machine,  200-208 
machine  with  automatic  sander, 

206 

wire  cut-off,  207 
single  conical  rolls,  200 
tempering  device,  202 
Chamotte  mass,  575 
material  for,  367 
or  cement,  364 
Chaptal,  formulae  by,  for  glazes  free 

from  lead,  529 
Charles  I.,  regulation  of  size  of  brick 

by,  14 

Chaser  mill,  371 
Checkers,  334 
Cheltenham,  Mo.,  clay,  58 
Chicago,  annual  consumption  of  brick 

in,  20 
Terra-Cotta  Co.,  introduction  of 

English  methods  by  the,  470 
Chimney    shafts,    setting     fire-brick 

forming  the  lining  of,  311 
China,  artistic  tiles  found  in,  556 
clay,  26 

and  kaolin,  85,  86 


China,  early  use  of  roofing  tiles  in,  555 

great  wall  of,  9 
Chlorine,  destruction  of  coke  ovens 

by  the  development  of,  324 
Christy  clay,  395 
Cincinnati,    annual   consumption    of 

brick  in,  20 
Standard  sewer-pipe,  427 

inability  of  the  Ak- 
ron      works       to 
make,  431 
Clarion  brick,  339 
Clay,  26-86 

advantage  in  calcining,  365 
and  grit,  finding  the  proportions 
of,  for  terra-cotta,  487 
mixing  of,  for  terra-cotta, 

488-491 

mixtures  of  clay,  machinery 
for  preparing,  reasons  for 
difference  of  opinion  as  to 
which  is  most  suitable, 
491,  492 

average  price  per  ton  of,  82 
belt,  the,  348 
Bischoff's  assay  of.  58 
bond,  59-61 

brick,  principal  constituent  of,  29 
burned,  as  roofing  material,  555- 

564 
burnt,    mixture    of,    with    crude 

clay,  367 

business,  lack  of  available  knowl- 
edge pertaining  to  the,  454 
-car,  bottom-dumping,  124,  125 

side-dumping,  123,  124 
caving,  danger  in,  118 
characteristic  property  of,  26 
colors  of,  26 
compounds  in,  26 
constitution  and  preparation  of, 

for  roofing  tiles,  568,  569 
conveying  and  grinding,  214-218 
of,   in  fire-brick  works,  348, 

349 

cost  of  placing  the,  in  the  tem- 
pering sheds,  118 
crude,  preparation  of,  for  grit,  488 
-crushers,  130-133 

universal  use  of,  125 
definition  of,  26 
dehydrated,  properties  of,  46 
density  of,  58 
deposits  of  New  Jersey,  average 

depth  of,  81 
supersession   of, 

81 
derivation  of  the  word,  26 


INDEX. 


605 


Clay,  determination  of  the  color  to 
which  it  will  burn,  34 
of  the  suitability  of,  35, 36 
difficulty  in  pulverizing,  240,  241 
digger,  mechanical,  118 
distribution  of  iron  in,  35 
-dust  tiles,  having  surfaces  in  re- 
lief or    intaglio,    manufacture 
of,  532,  536 
early  use  of,  1 
effect     of     alkaline     carbonates 


upon,  29 

carbonate  of  lime 
29 


upon, 


common  salt  upon,  29 
elevating  the,  to  the  disintegrator, 

128 

exploration  of,  by  boring,  35,  36 
exposure  of,  to  rain  and  frost,  126 
extraction  of,  by  mining,  65,  66 
fat,  definition  of,  36 
fault  in  the  preparation  of,  60 
fire  shrinkage,  of,  28 
for  drain  tile,  446,  447 

preparing  and  hand- 
ling of,  447-449 
enameled  brick,  406 
laying  fire-brick,  312,  313 
formation  of,  27 
function  of  sand  in,  29 
good  brick,  properties  of,  30 
grinding  the  water  out  of  the,  107 
grittiness  of,  46 
hauling,  448 

expense  of,  1 19 
improvement    in    machines    for 

moulding,  by  the  dry-clay  pro- 
cess, 242,  243 
ingredients  of,  26 
irregularity   of    composition    of, 

32,33 
knowledge   of   the    composition 

and  properties  of,  31 ,  32 
limits  of  shrinkage  of,  28 
"linear  shrinkage"  of,  28 
loss  to  materials,  in  weathering, 

260 
manipulation  of,  for  the  dry- clay 

process,  238,  239 
manner  of  mining,  62,  63 
mining   of,    for    building   brick, 

117-120 
mixer,  495 
mixing  of,  by  falling  the  bank, 

119,  120 

mixing  pug  mill,  494 
most  refractory,  composition  of, 

55 


Clay,  moulding  the,  89-92 

necessity  of  an  analysis  of,  58 

proper  preparation  of, 

125 

New  Jersey,  color  of,  82 
organic  matter  in,  55 
philosophy  of  the  flow  of,  through 

dies,  137, 138 
plastic,    machine    for    moulding 

roofing  tile  from,  585-588 
power  of,  to  pass  with  water  into 

a  dough-like  paste,  27,  28 
preparation  of,  for  pressed-brick, 
269 

for  roofing  tiles,  548 

in  London  tileries,  552 

the,  87,  88 

the,  for  the  dry-clay  process, 

238 
preserving  the  moisture  of,  in  the 

bank,  448 
proper  dryness  of,  in  the  dry-clay 

process,  239.  240 
purest,  found  in  nature,  26 
qualification   of  a,  for  building- 
brick,  33 

rare  minerals  in,  30 
reduction  of  stone  in,  492,  493 
of  the  natural  shrinkage  of, 

486 

refractory  nature  of,  55,  56 
roof,    non-conducting  properties 

of  a,  562 
screening  of,  61 

selection  of,  for  sewer-pipe,  425 
selecting  of,  for  the  dry-clay  pro- 
cess, 237,  238 

Shingle  Co.,  tile  factories  work- 
ing under  the  patent  of  the, 
560,  561 

shrinking  power  of,  248 
silicious,  55 
sizing  the,  107 
soaking  of,  126 
sorting  of,  63 
storage  of  in  sheds,  240 
substances  used  to  prevent  the 

matrix  adhering  to  the,  280 
tempered,  covering  of,  111 
tempering  and  preparing  of,  125- 

130 

tempering,  experiments  in,  127 
object  of,  89 
of,  88,  89 

of,  for  pressed-brick,  270 
terra-cotta,  80-85 
testing  of,  for  pressed-brick,  269 
thawing  of,  127,  128 


6o6 


INDEX. 


Clay,  the  result  of  decomposition  of 
granite  rocks,  32 

value  of  when  manufactured  into 
brick,  493 

value  of,  when  manufactured  into 
terra-cotta,  493,  494 

variation  in  the  composition  and 
quality  of,  46 

water  of  pores  of,  28 

water  of  shrinkage  of,  28 

weathering  of,  87,  88,  259,  260 

wintering  of,  448,  449 
Clays,  analyses  of,  56,  453 

building-brick,  30-36 

calcareous,  30 

chemical  analysis  of,  258 

classes  of,  27,  30 

determination  of  plasticity, 
moulding  and  drying  qualities 
of,  34 

determination  of  pugging  quali- 
ties of,  34 

determination  of  the  specific 
gravity  of,  59 

different,    experiments    with    in  , 
burning  with  natural  gas,  188 

efflorescence  of,  84 

essential  constitution  of,  45 

extraction  of,  61 

fire  or  refractory,  45-59 

for  glass  pots,  395 

for  terra  cotta,  treatment  of,  486- 
502 

for  the  terra-cotta  maker,  493 

foul  or  pure,  30 

geological  division  of,  26,  27 

Hudson  river,  36,  37 

Kittanning,  iron  in,  429 

mild,  30 

mixing  of,  449 

mixture  of,  for  terra-cotta,  485, 486 

much  valued  by  porcelain- 
makers,  formula  of,  85 

New  Jersey,  plasticity  of,  83 

ordinary  yellow  brick,  iron  in, 
28,29 

paving- brick,  38-45 

plasticity  of,  56,  57 

plasticity  of,  promoted  by  weath- 
ering, 363 

refractory,  pyrites  in,  326 

selecting  and  preparing  the,  for 
pressed-brick,  257-260 

selecting  of,  for  various  kinds  of 
building-brick,  34-36 

shale,  mining  of,  214,  215 

slipping  or  washing  of,  for  terra- 
cotta, 488 


Clays,  treatment  of,  with  acids,  364 
variety   and   extent   of,  in   New 

Jersey,  81 
very  refractory,  manipulation  of, 

371 
yielding     by     themselves    good 

glazes,  567 
Cleat,  moulding,  91 
Cleveland,    annual    consumption    of 

brick  in,  20 
Clod  crusher,  494 

Coal,  amount  of,  for  settling  fires,  99 
amount   of,  required   to   burn   a 

kiln  of  hand-made  brick,  101 
bituminous,    number   of  pounds 
of,  equal  to  one  cord  of  wood, 
179,  182 

common  salt  in,  324 
cost  of  in  America,  294 
dust,     abrasive     and     corrosive 

power  of,  307 
mixing  clays  with,  449 
measures,  clay  from  the,  48 
slack  for  fuel,  182 
table  showing  the  value  and  prop- 
erties of  various  kinds  of,  180- 
182 

Coals,  Westphalia,  coking  of,  321 
Cobalt  in  clay,  30 
Coblentz  clay,  58 
Coke-holders,    steel,    cover  tile    for, 

344 
oven  brick  and  tile,  325 

destruction    of,    by   the    de- 
velopment of  chlorine,  324 
work,  342 
use  of,  as  a  substitute  for  graphite, 

369 

Cokes,    salts   soluble   in   water    con- 
tained in,  324-326 
Colchester,     England,     old     Roman 

brick  re-used  at,  12 
Colors  for  enameled  brick,  prepara- 
tion of,  418,  419 
Columbus  sewer-pipe,  reason  for  the 

popularity  of,  430 
Columella  on  the  cultivation  of  the 

soil  and  drainage,  449,  450 
Combustion,  philosophy  of,  185,  186 
Continuous  kilns,  291-298 

drawbacks  in  the  use 

of,  293-294 
Conveying  and  grinding  clay,  214-218 

fire-clay,  357-360 
Cook,     Robert     Anderson,     on     the 

Mount  Savage  fire-clay,  50-53 
Cooling  enameled  brick  after  burning, 
422,  423 


INDEX. 


607 


Copper  in  clay,  30 

lost  art  of  producing  the  green, 
blue  and  red  of  the  ancients 
from,  527 

Cornwall,  kaolin  of,  85 
Covering  masses,  575 
Cover  tile,  for  steel  coke  holders,  344  , 
Cowen,  Jos.,  on  the  manufacture  of  I 
fire-brick  in  the  North  of  England  i 
and  Wales,  377 
Cracking  the  door,  99 
Crafts,  S.  P.,  on  the  comparative  cost 
of  burning  brick  with  oil  and  other 
fuels,  195-197 

Cream  body,  recipe  for,  413 
Creusot,  device  used  at,  to  counteract  I 
expansion  and  contraction  of  fire- 
brick, 369 

Crewe,   England,  device  used  at,  to 
counteract    expansion 
and  contraction  of  fire- 
brick, 369 
exhibition  of  art  tiles  at,  I 

520,  521 

Cribs,  drying,  157 
Crossly,  A.,  on  the  construction  of  a  | 

drying  floor,  161,  162 
Crotoii  Point  clays,  36 
Crowley,  D.  C.,  on  burning  brick  with 

natural  gas,  186 
Crucibles,  drying  and  tempering  of, 

380 
Crusher,  four- roll,  130 

improved  tailings,  217,  218 
two-roll,  130 
Cupola  blocks,  315 

iron,  section  of,  335 
lining  brick,  336 
shapes,  M'Kenzie,  315 
Cutting  and  slashing,  88 
Cyanogen  in  blast  furnaces,  321,  322 
withdrawal  of  alkalies  by,   323, 

324 
Cylinder  crusher,  use  of,  488 

DASHOUR,  pyramid  of,  5,  6 
Dawson,  H.,  Sr.,  on  the  burning 

of  paving  brick,  224 
Deep  blue  stain,  recipe  for,  414 
Delaware,  China  clays  in,  86 

Terra-Cotta     Co.,     Wilmington, 
Del.,    manufacture    of    sewer- 
pipe  by  the,  432-434 
Density  of  clays,  58 
Des  Moines,  Iowa,  clay  at,  43 
Diamond    Brick    Co.,    Kansas  City, 

Mo.,  clay  used  by  the,  42 
»        tiles,  554 


Die  Niedergesaess  patent  lubricating, 

139-141 
Die  of  various  brick  machines,  139 

oil  for  the,  271 

Digging,  mining,  and  marketing  fire- 
clays, 61-78 
Dinas  brick,  appearance  of,  388,  389 

manufacture  of,  389-391 
"clay,"  composition  of,  389 
discovery  of  the  use  of,  386,  387 
fire-brick,  386 

durability  of,  387 
occurrence  of,  389 
Diodorus   Siculus  on   the  decorated 

brick  of  Babylon,  403 
Dips,   application  of,  for  enameling 

brick,  416,  417 
for  enameled  brick,  415 
Disintegrator,   elevating  the   clay  to 

the,  128 
use  of  the,  126 
Dobies,  10 

Dodd's  carrier  for  horizontal  tile  ma- 
chine, 465-467 
Dolomite  in  clay,  26 
Dorsetshire,   England,  potter's  clay, 

analysis  of,  80 
Double-geared  pug-mill,  135 

pug-mill,  497 

Dowlais,  Wales,  device  used  to  count- 
eract expansion  and  contraction  of 
fire-brick,  369 

Down-draft  and  round  kiln,  182,  183 
kiln,    burning    drain-tile    in 

the,  457 
kilns,    for     burning    paving 

brick,  225,  226 
Drab  stain,  recipe  for,  414 
Drainage,  a  safe  guard  against  drouth, 

452 
benefits  of,  in  a  sanitary  point  of 

view,  453 
early,  450 

farm,  creation  of  capital  by,  454 
Drain-pipe,  barrow  for,  444 
-pipe,  shapes  of,  445 
-pipes,  device  for  preventing  the 
displacement  of,  in   the  kiln, 
442-444 
tile,    benefit   derived  from,   451, 

452 

burning  of,  457-461 
clay  for,  446,  447 
cracking  of,  455 
drying  of,  455-457 

in  open  sheds,  457 
factory,  location  of  a,  447 
firing  of,  458,  459 


6o8 


INDEX. 


Drain-tile,  its  manufacture  and  use, 

449-455 

-making  machines,  461-465 
systematizing  the   work 
"of,  447,448 
manufacture   and   use   of  in 

Illinois,  452,  453 
of,  446-467 
nesting  of,  453 
origin  of,  449 
preparing  and  handling  clay  ; 

for,  447-449 
price  of,  446 
shape  of,  446,  451 
Drier,  Bucyrus,  166-169 

flue  and  hot  floor,  163,  166 
how  to  devise  a,  163 
Wolff,  455 

Driers,  horizontal,  163 
flMj  petroleum  as  a  fuel  for,  192-195 

steam  works  for,  158-161 
Dry  and  wet  pan  combined  for  fire- 
clay, 373 
-clay,  a  misnomer,  235 

brick,  burning  of,  245-248 
difference   between   the, 
and  the  pressed-brick, 
256 

drying  of,  244,  245 
examination   of  samples 

of,  237 
firing  of,  246 
fuel  required  to  burn  a 

kiln  of,  248 
machines,  243,  244 
drawbacks  to,  243 
lack    of   knowledge 
of    those     having 
charge    of    them, 
243,  244 

strength  of,  243 
brickmaking,  causes  of  fail- 
ure in,  236 
in  St.  Louis,  235,  236 
requirements  for  success 

in,  236 
brick,  manufacture   of,  235- 

250 

opposition  to,  235 
setting  of,  245 

process,  advice  to  one  about 
to  undertake  the  mak- 
ing of  brick  by  the, 
240,  241 

difficulties  of  the,  239 
improvement      in      ma- 
chines   for    moulding 
clay  by  the,  242,  243 


Dry -clay  process,  manipulation  of  the 

clay  for  the,  238,  239 
preparation  of  the  clay 

for  the,  238 
selecting    clay   for    the, 

237,  238 

pulverizers,  241-243 
salmon  brick,  237 
Dryer,  hot  floor  or  flue,  150 

floor,    steam,    used   in   England, 

350-354 

Turley  &  Beyerly's,  354 
Dry  floors,  steam,  161-163 
Drying,  92-95 

and  tempering  refractory  articles, 

380-383 

artificial,  advantages  of,  221,  222 
general   advantages  of,   151, 

152 

boards  for  terra  cotta,  497-499 
brick  by  a  current  of  hot  air,  166 
by  the  pallet  system,  151 , 156, 

157 
classification  of  methods  of, 

150 

in  sheds,  advantages  of,  151 
in  the  sun,  disadvantages  of, 

150,  151 
with  exhaust  steam  from  the 

engine,  158-161,350 
cribs,  157 
drain  tile,  455-457 
floors,  hot  air,  354-357 
of  the  dry-clay  brick,  244,  245 
paving-brick,  221,  222 
room,  arrangement  of  a,  412 
shed,  construction  of,  93,  94 

for  pressed  brick,   252,  271, 

272 

steam  for,  500 

tempered-clay  brick,  150-153 
terra-cotta,  evaporation  of  water 

in,  483 
terra-cotta,  general  rules  for,  501, 

502 

tunnel  system  of,  150 
Dry-pan    and   pug  mill  mixer  com- 
bined for  fire-clay,  373,  374 
the,  215-217 
press-brick  machine,  clay  for  the, 

34 

Dueberg  kiln,  the,  297 
Dump-cars,  359,  360 

and  winding  drums,  120-125 
Dunnachie  kiln,  299-303 

adoption  of  the,  for 
burning  silica  brick, 
393 


INDEX. 


609 


Dust-clay    intaglios,    sharpness    and  ! 
definition  of  texture  of  reliefs  made 
from,  535 

Dutch  directions  for  glaze,  572,  573 
kiln,   burning  drain  tile  in  the, 

457,  459,  460 
ordinary  open,  101 
setting  dry-clay  brick  in  the, 

245 
setting  pressed  brick  in  the, 

265 
tiles,  glazes  for,  576 

Meissen  masses  for,  575,  576 
raw  glazing  of,  574-576 
white  enamel  for,  579 

EAGLE  Double  Mould  re-press,  283 
Earthen     pipe,    conveyance    of 
water  in,  by  the  Romans,  450 
Earthenware  pipes,  curved,  machine 
for  forming  sockets  on,  437-440 
pipes,  curved,  machine  for  mak- 
ing, 435-137 
Edward   IV.,  law  of,  regulating  clay 

for  roofing-tile,  546 
Efflorescence  of  clays,  84 
Egypt,  brick  of  ancient  and  modern,  4 

pottery  in,  1 

Egyptian  brick,  stamped  with  prae- 
nomens  and  names  of  mon- 
archs,  7 

statues  in  terra-cotta,  468 
Egyptians,  children  of  Israel  making 

brick  for  the,  3 
the  oldest  tile-makers,  513 
Elberg,    George,    machine     for    the 
manufacture   of    flooring-tiles,    in- 
vented by,  536-5  U 
Elbers,  A.  D.,  on  carbon  deposits  in 

fire-brick,  326-330 
Elder,  John  R.,   on  burned  clay  as 

roofing  material,  555-564 
Electrotypes  for  making  intaglios  and 

reliefs,  533 
use  of  an  intaglio  as  a  mould  for, 

534 
Elevating  devices  for  brick  and  tile, 

455 
Elevator,  endless,  455 

platform,  455 
Eliottsville  works,  sewer-pipe   press 

used  at  the,  427 
Elizabeth,  brickmakiug   in  England 

in  the  time  of,  13 
El  Paso,  manner  of  making  very  hard 

and  durable  brick  at,  '^3 
Elutriating,   storing  and  weathering 
fire-clay,  362-364 

39 


Emerald,  J.  W.,  clay  used  by,  44 
Enamel,  black,  532 

colored,  production  of,   531,  532 
deep  brown  violet,  532 
golden  yellow,  531 
green,  532 
pale  blue,  531 
red,  532 
violet,  5U 

white,  for  Dutch  tiles,  579 
Enameled  brick,  clay  for,  406 

cooling  of,  after  burn- 
ing, 422,  423 
defects  engendered  in, 

421 

dips  for,  415 
firing  of,  416,417,421. 

422 

first  body  for,  415 
history  of,  402 
kilns  for,  420,  421 
manufacture    of,    402- 

424 
preparation    of    stains 

for,  418,  419 
secrecy  maintained  by 
the      manufacturers 
of,  in  England,  404. 
405 
setting  of,  in  the  kiln, 

416,  419,  420 
Enameling  brick,  412-419 

application  of  dips  for, 

416,417 
explanations    of,  417- 

419 
instructions    for,    416, 

417 

stains  for,  414,  415 
slate  waste  brick,  423,  424 
Enamels,  easily  fused,  403 

experimenting  with  various,  40o 
variations  in  the  fusing  point  of, 

404 
England,  art  of  enameling  brick  in, 

40J 
brick     construction    in,    in    the 

reign  of  Henry  VI. ,  13 
brick  in  the  reign  of  Alfred  the 

Great,  13 

brickmaking  in,  in  the  time  of 
Henry  VIII.  and  of  Elizabeth, 
13 

chief  building  material  in,  14 
clay  used  for  terra-cotta  in  the 

north  of,  80 

earliest  brick  building  in,  13 
examples  of  early  brick  work  in,  13 


6io 


INDEX 


England,  manufacture  of  brick  in,  by 

the  Romans,  12 

manufacture  of  fire-brick  in,  375 
moulding  fire-brick  in,  377,  378 
North   of,    manufacture   of   fire- 
brick in,  377 

old  Roman  brick  re-used  in,  12 
plain  roofing  tiles  used  in,  544 
primitive  churches  of,  12,  13 
pug  mill,  employed  in,  548 
regulation  of  the  size  of  brick  in, 

14 
secrecy  maintained  at  the  Royal  ! 

Potteries  in,  454 

secrecy  maintained  by  the  manu- 
facturers of  enamel  brick  in, 
404,  405 

steam  dry- floor  used  in,  350-354 
taxation  of  brick  in,  14 
use  of  gutter  tile  in,  544 
use  of  the  fire-brick  mill  in,  372 
English  brick,  volume  and  size  of,  294 
Etruscan  tiles,  508 

Eudaly,   W.  A.,  on   burning  paving- 
brick,  225 
on  paving-brick  clay,  38, 

89 

on  the  construction  of  a 
paving  -  brick  plant, 
210,  211 

statement  by,  of  the 
number  of  pounds  of 
bituminous  coal  equal 
to  one  cord  of  wood, 
179,  182 
Europe,  cost  of  burning  1000  brick 

in,  294 

market  price  of  brick  in,  294 
Western,  art  of  enameling  brick, 

troduced  in,  402 

Evansville  Pressed-Brick  Co.,  manu- 
facture of  paving  brick  by  the,  232, 
233 

Ewart  J.  C.  &  Co.,  roofing  tiles  made 
by,  554,  555 

FARRANDSVILLE,  Pa.,  fire-clay, 
analysis  of,  48 

Farrandsville,  Pa.,  fire-clays  of,  47 
Fawn-color  covering  mass,  575 
Fayoom  and  the  Delta  of  the  Nile,  6 
Feed  hole  blocks,  325 
Feldspar,  32 

extraction  of,  61 

kaolin  and  fire-sand,  digging  of, 

66 

Feldspars,  kaolin,  fire  sands,  and  fire- 
clays, method  of  analysis  for,  78-80 


Fire  box  arches,   locomotive,  blocks 

for,  340,  341 
brick,  air-drying  of,  M82 

basis  of  success  in  the  manu- 
facture of,  362 
best  way  of  obtaining  a  high 

grade  of,  381,382 
burning  of,  383,  384 
bursting  of,  327-330 
carbon  deposits  in,  326-330 
for  furnaces,  394 ,  395 
method  of  setting,  395 
care  of,   before   being   used, 

310 
chemical  changes  in  burning, 

311,312 

clay  for  laying,  312,  313 
complete     homogeneity,     in 

the  interior  of,  371 
cost    of    moulding    and    re- 
pressing, 378 
crushing  weight  of,  309 
devices  to  counteract  expan- 
sion and  contraction  of,  369 
drying  and  tempering  of,  380 
of,  in  the  United  States, 

381 

effect  of  iron  on,  335,  336 
English  process  of  moulding, 

377,  378 
essential  qualities  of  a  good, 

306 
expansion  and  contraction  of 

mixtures  for,  369 
of,  311 
factories,   St.  Louis,   method 

in  use  in,  376 
factory,    arrangement    of    a, 

349,  350 
failure  and  wear  of  a,  in  the 

furnace,  60 
for   the   various  parts    of    a 

structure,  309 
furnace  for  testing,  52,  53 
grades  of,  330 

irregular  wearing  of,  in  fur- 
nace roofs,  307,  308 
manufacture,  360-384 

constitution  of  hydrated 
silicates  of  alumina, 
used  in,  54 

manufactured    by   the    soft- 
mud  process,  drying  of,  382 
mechanical       strength      de- 
manded from,  371 
mill,  372 

mixture  for,  by  human  labor 
and  mechanical  means,  369 


INDEX. 


of 


Fire  brick,  mixtures  for,  332 

most    appropriate     form 

kiln  for  burning,  383 
most  infusible  known,  306 
moulds  for,  375,  377 
Mount  Savage,   analyses  of, 

48,  49 

nature  of  service  required  of, 
in  the  different  parts  of  the 
furnace,  339-341 
nine-inch  shapes,  314 
object  of  pressing,  375 
plants,  location  of,  47 
pressing  and  moulding,  375- 

380 

properties  of  a  good,  307 
selection  of  the  materials  for, 

370 

shapes,  313 
shrinkage  in,  307 
silica,  3-6-394 

fire-brick,  carbon  fire- 
brick for  furnaces,  glass 
pots  and  gas  retorts, 
manufacture  of,  306- 
401 
slow,  progressive  burning  of, 

311 

sorting  of,  330-336 
special  shapes  of,  330 
steam  pressing  of,  376 
storage  of,  383 
structure  of  the,  60 
testing  the  power  of,  to  resist 

corrosive  influence,  312 
usual    quantities  of  mixture 

for,  368,  369 
well  manufactured,  color  of, 

311 

works,    and    their    construc- 
tion, 345-360 
boiler  for,  347 
branches    of    science    a 
manager  of,  should  be 
acquainted   with,   361 , 
362 

conveyingclay  in, 348,349 
desirability  of  practical 
and  theoretical  knowl- 
edge by  the  manager 
of  a,  360-362 
drawing  plans  for,  346 
engine  power  for,  347 
Ohio  and  Pennsylvania, 
hot  floors  used  in,  356, 
357 

clay,  amount  of,  usually  kept  on 
hand,  363 


Fire  clay,  analyses  of  silica  in,  54 
calcining  of,  365,  366 
change  in  refractoriness  of  a, 

by  grinding,  51 
colors  of,  46,  47 
conveying  of,  357-360 
dry  and  wet  pan  combined 

for,  373 
dry  pan  and  pug-mill  mixer 

combined  for,  373,  374 
formula  for  the  calculations 

in  getting  at  the  value  of  a, 

geological  formations  of,  46 
grinding  and  tempering  of, 

370-375 
of,  methods  in  America, 

372-375 

handling    and    transporting 
of,   by  the   Union  Mining 
Co.,   Mount  Savage,  Md., 
357-359 
mines,  care  of,  67 

streaks  or  spots  in,  67 
process  of  grinding  and  tem- 
pering of,  in  use  in  Ohio, 
374,  375 

removal  of  impurities  from, 
by  the  action  of  the 
weather,  363 

retorts,      tiles     and     blocks 
necessary     in     setting     a 
bench  of,  in  gas  works,  343 
Spanish,  366 

storing,  weathering  and  elu- 
triating, 362-364 
washing  of,  370 
wet  pan  process  for,  372,  373 
clays,  45-59 

and  associated  refractory  ma- 
terials, tables  of  analyses 
of,  68-76 

characteristics  of  all,  57,  58 
digging,  mining  and  market- 
ing, 61-78 
elutriation  of,  364 
feldspars,    kaolin,    and    fire 
sands,  method  of  analysis 
for,  78-80 
fire  tests  of,  77,  78 
important  properties  of,  53-59 
mixing  of,  368-370 
varieties  of,  47 
hard  and  grind,  explanation  of, 

418 
insurance,  rate  of,   in  Germany, 

561 
losses,  in  the  United  States,  561 


612 


INDEX. 


Fire  places,  tile  for,  329 
sand,  extraction  of,  61 

feldspars,    kaolin    and    fire- 
clays,  method  of  analysis 
for,  78-80 
kaolin,  and  feldspar,  digging 

of.  66 

shrinkage  of  clay,  28 
stones,  307 
tests,  77.  78 

Fires,  building  up  of  the,  98 
crossing  the,  98 
head,  102 

settling,  when  given,  100 
Firing  of  drain  tile,  458,  459 
of  ornamental  tiles,  526 
the  Hoffman  kiln,  296,  297 
Fish  Pressed  Brick  Co.,  Columbus,  O., 

brick  manufactured  by  the,  297 
Flanders,  first  use  of  pantiles  in,  544 
Floor,  brickmaking,  heating  and  con- 
struction of  a,  408-411 
tile,  344 
Flooring  tiles,  wet-clay,  manufacture 

of,  536-541 

Floors,  preparation  of,  87 
Florida,  brickmaking  in,  21 
Flue  and  hot  floor  drier,  150,  163-166 
Flues,  rabbeted  tile  for,  344 
Former,    peculiar    form    of  the,    in 
Chambers  brick  machine,  203,  204 
Fort  Smith,  Ark  ,   analysis  of  shale 

clay  used  at,  44 

Forty-two  high,  definition  of,  95,  96 
Four-roll  crusher,  130 
France,    introduction    of   the   art   of 

enameling  brick  in,  402 
manufacture  of  glazed  and  enam- 
eled tiles  in,  528—531 
roofing  tile  in,  557 
Fredericks,  Monroe  &  Co  ,  fire-brick 

shapes  carried  in  stock  by,  313 
Frey,  F.  rC.,  on  paving  brick  clay,  39 
Frey-Sheckler  Co.,  machinery  made 
by  the,  120,  121-125.  128.  137,  143- 
150,  166-169,  173-175,  215-218,  2-19, 
250,  282,  283,  455,  461-464. 
Friction  winding  drum,  120,  121 
Frontons,  543 

Frye,  Miss,  discovery  by,  527 
Fuel,  coal  slack  for,  182 

cost  of,  in  Trenton,  N.J.,  268 
for  burning,  274 

paving  brick,  226-228 
gas,  use  of,  for  burning  vitrified 

brick,  222 

importance  of  saving  of,  to  the 
European  brickmaker,  294 


Fuels  for  terra-cotta,  505,  506 
Furnace,  annealing  for  glass  pots,  398 

arch  tile  for,  534 

failure  or  wear  of  a  brick  in  the,  60 

for  testing  fire-brick,  52,  53 

nature  of  service  required  of  the 
brick  in  the  different  parts  of 
the,  339-341 

roofs,  irregular  wearing  of  fire- 
brick in,  307,  308 

Furnaces,  bricks  for  different,  and  for 
different  parts  of,  306,  307 

carbon  fire-brick  for,  394.  395 

glass,  use  of  silica  brick  in  the 
construction  of,  387 

open  hearth,  use  of  silica  brick 
in  the  construction  of,  387 

silica  brick  for,  387 
Furniture,  invention  for  the  produc- 
tion of,  596-598 

mosaic  plates  for,  invention  for 
manufacturing,  592-595 

p  ALESBURG,  111.,  clay  used  at,  42 
VJT     Gallimore,  Wm.  W.,  524 
Canister,  386 

' '  Canister ' '  brick,  composition  of,  393 
Garnkirk,  Scotland,  clay  of,  58 
Garrett     &     McManigal,    clay    used 

by,  43 
Gases  of  coke  ovens,  chlorine  in  the, 

324 
Gas,  fuel,  for  burning  vitrified  brick, 

222 
natural,  analysis  of,  186 

burning  brick  with,  186-191 
drain  tile  with,  460.  461 
cost  of  burning  with,  189 
retorts,  399-101 

glass   pots,    fire-brick,   silica 
fire-brick  and  carbon  fire- 
brick for  furnaces,  manu- 
facture of,  306-401 
various  forms  of,  399,  400 
weights  and  sizes  of,  401 
works,  tiles  and  blocks  necessary 
in  setting  a  bench  of  fire  clay 
retorts  in,  343 
Gates,  W.  D  ,  on  paving  brick  clay, 

39,40 
Gear  and  friction  winding  drum,  121- 

123 

German  brick,  volume  and  size  of,  294 
clays  for  glass  pots,  395,  396 
iron  districts,  daily  output  of  pig 

iron  in,  316 

Germany,   manufacture  of  brick   in, 
by  the  Romans,  12 


INDEX. 


613 


Germany,  rate  of  fire  insurance  in,  561  ' 
Giant  machine,  die  of  the,  139 

machines.  149 
Gibson.  L.    H.,   on  burned  clay  for 

covering  houses,  557,  558 
Glass  furnace  brick,  322 

house  pots,  drying  of,  381 
ovens,  material  used  in  the  con- 
struction of,  398 
pots,  395-399 

annealing  furnace  for,  398 
gas  retorts,   fire-brick,  silica 
fire-brick,  and  carbon  fire- 
brick for  furnaces,  manu- 
facture of,  306-401 
making  of,  397 
mode  of  shipping,  397 
preparation  of,  for  use,  397. 

398 

removal  of,  from  the  anneal- 
ing furnace,  398 
size  and  weight  of,  396 
Glaze,  application  of  the,  to  roofing 

tiles,  568 
azure  blue,  576 
black,  530 
blue,  530 
brown,  530 
cheap,  especially  for  the  colored 

mass,  575 
colorless,  530 
composition,  531 
constitution  of,  565,  566 
dark  red,  576 
dark  violet  brown,  570 
deep  red,  576 

Dutch  directions  for,  572,  573 
finer,  for  white  tiles,  575 
golden  yellow,  570 
green,  530,  570 
influence  of  sand  on,  566 
lead,  readily  fusible,  578 

refractory,  578 

mixture,  good,  formula  for,  576 
most  simple,  574 
pale  blue,  570 
violet,  570 
white,  424,  576 
yellow,  530 

Glazes,  abundance  of  material  for,  567 
containing  lead,  table  of,  530, 531 
defects  of,  after  burning,  568 
for  Dutch  tiles,  576 
for  roofing  tiles,  5 15.546,577-581 
free  from  lead,  fusing  point  of, 

581 

preparation  of,   529, 
530 


Glazes,  good,  clays  yielding  by  them- 
selves, 567 
higher  and  lower  fusing  points  of, 

580,  581 

lead,  temperature  for,  579 
mixtures  for,  569 
most  important,  for  roofing  tiles, 

580 

readily  fusible,  581 
nature  of,  to  be  used,  578 
Prof.  Weber's  method  of  testing, 

578 

recipes  for,  413 

resistance  of,  to  atmospheric  in- 
fluences, 577,  578 
various  shades  of  color  of,  5(i8 
with  a  determined  color  for  deco- 
ration, 567 

Glazing  masses,  coloring  of,  570 
mass  for  mending  before,  575 
plain,  of  roofing  tiles,  572,  573 
process  of,  571 
raw,  of  Dutch  tiles,  574-576 
roofing  tiles,  564-574 
sands  highly  valued  for,  566,  567 
"with  salt,  427,  428 
Glenboig  Union  Fire  Clay  Co.,  Lim- 
ited, of  Glasgow,  Scotland,  hot  air 
drying  floor  of  the,  354-856 
Glenboig  Union  Fire  Clay  Co.,  Lim- 
ited, of  Glasgow,  Scotland,  mining 
of  fire-clay  by  the,  68 
Gluts,  drying  the,  before  re-pressing, 

262,  263 

for  pressed  brick,  254 
moulding  the,  260-262 
re- pressing  the,  272 
Going  through  the   sweat,  explana- 
tion of,  83 

Gouge  spade,  the,  63 
Granulating  pug-mill,  128-130 
Grape  Creek  Clay  Co.,  111.,  shale  clay 
used  by  the, 
45 

manufactu  re 

of   paving 

brick      by 

the,  231 

Graphite,  use  of  coke  as  a  substitute 

for,  369 

Grass  green  stain,  recipe  for,  415 
Grate  backs,  set  of,  X40 
Graves,  Willis  N.,  kiln  invented  by, 

287-291 

Gray  son,    Lowood    &  Co.,   composi- 
tion of  "ganister"  brick  made  by, 
393 
Great  wall  of  China,  9 


614 


INDEX. 


Greece,  inferior  quality  of  the  brick 

made  in,  11 

Greeks,  ancient,  use  of  brick  by  the,  10 
and  Romans,  description  of  roof- 
ing tiles  used  by  the,  543 
use  of  tiles  among  the,  518 
Green  covering  mass,  575 

houses;  rabbeted  tile  for,  344 
Grinding  and  conveying  clay,  214-21 8 
tempering    fire-clay,    370- 

375 

pan,  the,  371 

Grit  and  clay,  finding  the  proportion 

of,  for  terra- cotta,  487 

mixing  of,  forterra-cotta, 

488-491 

preparation  of,  488 
Grog,  84 

or  sand  in  ornamental  work,  281 
Gross  Almerode  clay,  395 
Guthrie  kiln,  295 
Gutter  tiles,  544 

HALL,  Alfred,  improvement  in  the 
construction  of  pug 
mills  by,  104-106 
improvement  inr  the 
construction  of  terra- 
cotta kilns,  invented 
by,  506-508 

Hampton  Court  Palace,  13 
Hand-made   brick,    amount   of    coal 
required    for  a   kiln 
of,  101 

burning  of,  97-101 
making  and  burning  a 

kiln  of,  87-114 
tools    and     appliances 
used   in   the    manu- 
facture of,  101-103 
Hand  press-gang,  composition  of  the, 

temperer,  work  of  the,  88 
Harbison  &  Walker  Co.,  on  the  grades 
of  brick 
adapted  to 
particular 
parts  of  the 
furnace,  339- 
341 

special  shapes 
of  fire-brick 
manufactured 
by  the,  330 

washing  m  a  - 
chine  for  fire- 
clay used  by 
the,  370 


Haverstraw,  burning  brick  with  gas 

at,  190,  191 
clay,  36.  37 
cost  of  burning  brick  with  coal 

at,  190 

cost  of  wood  at,  191 
moulds;  90,  91 
Head  fires,  102 

Hearth -bottoms,  carbon-brick,  319 
Heating  furnace  blocks,  Siemens,  333 
Henry  VI.,  brick  construction  in  the 
"  reign  of;  13 
VIII.,  brickmakiug  in   England 

in  the  time  of,  13 
Herodotus  on  the  brick  used  in  the 

walls  of  Babylon,  4 
Hillar,  use  of  ancient  brick  for  build- 
ing houses  in,  4 
History  of  brick,  1-25 
Hoffman,    F.,    on    the   principal   ad- 
vantage of  his  kiln,  183 
kiln,  292-296 

application    of    the    to    the 

United  States,  295,  296 
cost  of  burning  brick  in  the, 

183 
drawbacks    in    the    use    of, 

293,  294 

firing  the,  296,  297 
modification  of  the,  295 
Holland,  chief  building  material  in, 

14 
Hot  air  drying  floors,  354-357 

floor  or  flue  dryer,  150,  163-166 
floors  used  in  Ohio  and  Pennsyl- 
vania fire-brick  works  356,  357 
water  tempering,  127 
Houses,  adobe,  10 

burned  clay  for  covering,  557,  558 
Hawara,  pyramid  of,  5,  6 
Hudson  river  brick  clays,  36,  37 

TLLAHOON,  pyramid  of,  5 

Illinois,  manufacture  and  use  of 

drain  tile  in,  452,  453 
Imbrices,  543 

Improved  Centennial   brick  and  tile 
machine,  with  new  pattern  side-cut 
delivery  table,  143-145 
Incline,  three-rail,  358 
Indiana,  drain  tile  in,  453 

starting  of  a  roofing  tile  factory 

in,  558,  559 

Intaglios,  dust  clay,  sharpness  and 
definition  of  texture  of  reliefs  made 
from,  535 

Intaglio  figure,  plan  of  a  tile  with  a, 
532,  533 


INDEX. 


6I5 


Intaglios  of  natural  objects,  manner 

of  obtaining,  534 

Intaglio,  use  of  an  as  mould  for  elec- 
trotypes, 534 
Intarsia  surfaces,  596-598 
Iowa  drain  tile  in,  453 
Iron  cupola,  section  of,  335 
distribution  of,  in  clay,  35 
effect  of,  on  fire-brick,  335,  336 
oxide    of,    conversion     of,    into 

peroxide,  98 
in  clay,  26 

phosphate  of,  in  clay,  30 
proportion  of,  in  clay,  56 
pyrites  in  clay,  26 
Israel,  children  of,  making  brick  for 

the  Egyptians,  3 
Italy,     mediaeval    ecclesiastical    and 

palatial  architecture  of,  13,  14 
Ivory  body,  recipe  for,  413 

JAPAN,  artistic  tiles  found  in,  556 
Jews,  tiles  of  the.  518 
use  of  ornamental  tiles  by 

the,  515 
Jones,  A.  O.,  on  burning  street- paving 

brick,  223 

on  paving-brick  clay,  40 
on   the  manufacture  of  pav- 
ing-brick, 231 

KANSAS,  drain  tile  in,  453 
use  of  adobes  in,  9,  10 
Kaolin,  26 

fire  sand  and   feldspar,   digging 

of,  66 

fire  sand,  feldspars  and  fire-clays, 
method  of  analysis  for,  78,  80 
Kaolinite,  30 
Kaolin,  meaning  of  the  term,  85 

or  China  clay,  85,  86 
Kaolins,  extraction  of,  61 
Kiln,  admission  of  air  into  the,  10  > 
calcine,  381-386 
detection  of  any  cold  place  in  the, 

99 

device   for    preventing    the   dis- 
placement of  drain-pipe  in  the, 
442-U4 
down-draft,  burning  drain  tile  in 

the,  457 

Dueberg,  the,  297 
Dunnachie,  299-303 
Dutch,  burning  drain  tile  in  the, 

457.  459,  4(30 
Guthrie,  295 
Hoffman,  292-296 


Kiln,  Hoffman,  application  of  the,  to 
the  United  States,  295,  296 
firing  the,  296,  297 
modification  of  the,  295 
hot,  98 

making  and  burning  a,  of  hand- 
made brick,  87-114 
management  of  the,  in  burning 

paving  brick,  228,  229 
Mendheim,  297,  298 
most    appropriate    form    of    for 

burning  fire  brick,  383 
of  brick  ready  to  fire,   invested 

capital  represented  by  a,  273 
of  dry  clay-brick,  fuel  required 

to  burn  a,  248 
of  hand-made  brick,  amount  of 

coal  required  to  burn  a,  101 
open  or  Dutch,  setting  dry  clay- 
brick  in  the,  245 
open  top,  183,  184 

burning  drain  tile  in  the, 

451,459,460 

plastering  or  daubing  the,  96 
proper  amount  of  settling  in  the, 
:§     100,  101 

purpose  it  has  to  serve,  313 
railway,  291 

removing  the  brick  from  the,  274 
roof  of  the,  98 
roofs,  permanent,  303-305 
round  or  down-draft,  182,  183 
setting  brick  in  the,  169-172 

enameled  brick  in  the,  416, 

419,  420 
pressed  brick  in  the,  252,  253, 

265-268 

the  green  brick  in  the,  95-97 
shelter,  the,  97 
ten  courses  of  brick  set  on  the 

bench  in  the,  96 
time     required     to    burn    a,    of 

pressed  brick,  265,  266 
watches  around  the,  102 
Kilns,  284-305 
annular,  101 
applicability  of  natural  gas  to  all 

manner  of,  188,  189 
brick  first  burned  in,  by  the  Ro- 
mans, 11 

calcining,  365,  366 
continuous,  291-298 

drawbacks  in  the  use  of,  293, 

294 

for  burn  ing  paving-brick,  225,  226 
coal,  97 

enameled  brick,  420,  421 
sewer-pipe,  434 


6i6 


INDEX. 


Kilns  for  terra-cotta,  502-505 

wood,  97 
location     of,     in     a     terra-cotta 

factory,  484 
open-top,     proper     management 

of,  469,  460 
regenerative,  298-803 
square  top,  182 
temporary,  284-287 
terra-cotta,  improvement  in  the 

construction  of,  506-508 
up  and  down  draft,  287-291 
used  in  the  London  tileries,  552, 

553 

Kittanning  clays,  iron  in,  429 
Knoblauch.   Dr.,    on    the   coking   of 

Westphalia  coals,  321 
Korea,  artistic  tiles  found  in,  556 

IADLE  nozzles,  334 
,     Laggara,  pyramid  of,  glazed  tile 

used  in  the,  513,  514 
Latin  cities,  material  used  in  the  early 

buildings  of  the,  10 
Lawshe,  Mr.,  explanation  by  of  the 
manufacture   of    ornamental   tiles, 
522-526 
Layard,  on  the  brick  from  the  ruins 

of  Babylon,  4 

Leach  patent  table,  464,  465 
Lead-poisoning,  532 
Lean  materials,  366-368 
Lepidolite,  31 

Light  blue  stain,  recipe  for,  414 
Lime,   carbonate   of,   effect   of  upon 

brick-clay,  29 

carbonate  of,  in  clay,  26,  33 
pebbles  in  clay,  33 
sulphate  of,  in  clay,  26 
stone  diffused  in  clay,  33 
Limit  of  shrinkage,  247  " 

water  shrinkage,  246,  247 
Limoges,  France,  kaolin  of,  85 
Lithia  in  clays,  31 

Little    Wenham    Hall,    Suffolk,    the 
earliest  true  brick  building  in  Eng- 
land, 13 
Loams,  30 

Locomotive  blocks  for  fire-box  arches, 
340,  341 

fire-box  arches,  323 
Lodon  tileries,  preparation  of  clay  in, 

552 
Lollards'  Tower,  of  Lambeth  Palace, 

13 
London  Clay  Co.,   of  London  Mills, 

111.,  clay  used  by  the,  45 
tileries,  kilns  used  in  the,  552,  553 


London,  universal  use  of  brick  in,  after 

the  great  fire  of  1666,  14 
Louisiana,  brickmaking  in,  21 
Lower  bench,  f'5 

Low,  J.  G.  &J.  F.,  specimens  of  art- 
tile   soda   fountains  made    by, 
521 ,  522 
John  G.,  commencement  of  tile 

making  by,  519 
premium  awarded  to,  for  the 
best  collection  of  art  tiles, 
521 

process   of  forming   grooves 
on  the  backs  of  tiles  em- 
ployed by,  536 
process    of    surfacing    tiles, 

invented  by,  532-536 
Liirmann,    Fritz    W  ,    on    refractory 
brickwork  of  blast-furnaces  and  its 
preservation,  313-326 
Lute,  the,  102 

MACHINE,  best,  for  pressed  brick, 
270 
for  moulding   roofing   tile   from 

plastic  clay,  585-588 
improved   Centennial  brick   and 
tile,  with   new  pattern  side-cut 
delivery  table,  143-145 
made  brick,  partially  drying  of, 

for  repressing,  152 
Mascot,  with  daisv  cutting  table, 

141-143 

Machinery,  description   of  the  most 
modern,    and   manufacture    of 
tempered-clay  brick,  115-199 
division  of  the  process  of  brick- 
making  by,  117 

for  preparing  clay  and   mixtures 

of  clay,  reasons   for  difference 

of  opinion  as  to  which  is  most 

suitable.  491,  492 

lubricants   for,   used   in    making 

brick  which  is  to  be  enameled, 

407 

modern,  drawbacks  in,  117 
Machines,  drain-tile  making,  461-465 
for  moulding  clay  by  the  dry-clay 
process,  improvements  in,  242, 
243 
required  for  a  terra-cotta  plant, 

494 
used    in    making    the    glut    for 

pressed  brick,  261 ,  262 
Mahoganv   brown    stain,   recipe   for, 

414 

Maine,  weathering  of  clay  in,  87,  88 
Malm,  30 


INDEX. 


6I7 


March,  Ernest,  method  of,  488 
Marketing,  digging  and  mining  fire- 
clays, 01-78 
Marls,  30 

Maryland,  China  clays  in,  86 
Mascot  machine,  die  of  the,  139 

with  daisy  cutting  table, 

141-148 
Matrix,   substances  used  to   prevent 

adherence  to  the  clay,  280 
Mazarine  blue,  recipe  for,  415 
McKenna's  patent  checker,  334 
M'Kenzie  cupola  shapes,  315 
Meissen  masses  for  Dutch  tiles.  575, 

57(3 

Mendheim  kiln,  the,  297.  298 
Merrill  roofing  tile  machine,  581-584 
Mesopotamia,  use  of  unburned  brick 

in,  8,  9 

Mexico,  use  of  sun-dried  brick  in,  9 
Mica,  32 

Michigan,  drain  tile  in,  453 
Middleport,  O.,  clay  at,  43 
Mills,    overgeared  and   undergeared, 

347.  348 

Milwaukee  cream-colored  brick,  31 
Mineral  Point,  O.,  clay,  395 

fire-clay  at,  47 
Minerals,  rare,  in  clay,  30 
Mining  clay  for  building  brick,  117- 

120 
digging,  and  marketing  fire-clays, 

81-7H 

shale  clays,  214,  215 
Mississippi,  brickmaking  in,  21 
Missouri  clays,  58 

drain  tile  in,  453 
Modelers,  qualifications  of,  469 
Modeling  terra-cotta,  508-510 
Model,  process  of  making  a,  525 
Mohammedans,  revival  of  tile  mak 

ing  by  the,  519 
Monks,  revival  of  tile  making  by  the, 

519 
Moon,  short,  the,  102 

the,  99 
Moors,    introduction    of   the    art    of 

enameling  brick  by  the,  402 
Morrison,  R.  B.,  on  setting  brick  in  ! 

the  kiln,  169-172 
Morse,  Edward  L.,  on  the  older  form 

of  roofing  tiles,  555 
Mortier,   P.,   description  of  the  city  ; 

hall  of  Amsterdam  by,  14,  15 
Mosaic,  Florentine,  591 

plates,  invention  of  Robert  EHz- 
ner,  for  manufacturing,  592-595 
process  of  making  a,  591 


Mosaic,  Roman,  591 

work  in  marble,  590 

of  glass,    fine  specimens  of, 

590 
Mosaics,  cheap,  592 

derivation  of  the  name,  590 
manufacture  of,  590-595 
Moulder,  duty  of  each,  90 
Mould  for  pressed  brick,  251,  252 
size  of  the,  90 

for  enameled  brick,  407 
Moulding  and  pressing  fire- brick,  375- 

380 
paving    brick, 

219-221 

by  the  slop  method,  94 
cleat,  91 

gang,  constitution  of  a,  92 
gluts  for  pressed  brick,  260-262 
methods  of,  90-92 
roofing  tile    from    plastic    clay, 

machine  for,  585-588 
of  roofing  tiles,  549 
sand,  252 

stiff-clay  brick,  137-139 
'table,  549 
the  clay,  89-92 
Moulds  for  fire  brick,  375,  377 

sanding  the,  for  pressed  brick,  270 
single  cast  iron,  252 
Mount  Savage,  Md.,  analysis  of  fire- 
clay of,  49 
fire-brick,     analyses 

of,  48,  49 

fire-clays,  47,  48-53 
mine,  handling  and 
transporting    fire- 
clay at  the,  357-359 
peculiarity     of    the 
deposit  of  clay  at, 
50 

Mud-brick,  common  clay  for,  34 
Muffle  terra-cotta  kilns,  502-505 
Munich,  manufacture  of  colored 

glazed  tiles  in,  531 ,  532 
moulding  flat  roofing  tiles  in,  570 
roofing  tiles  used  in,  and  mode  of 

tiling,  571,  572 

roof  of  the  Ludwig  church  at,  565 
Murtagh,  J.,  device  of,  for  preventing 
the  displacement  of  drain-pipe  in 
the  kiln,  442-444 

NATURAL  gas,  analysis  of,  186 
burning    brick   with, 

186-191 

drain     tile     with, 
460,  461 


6i8 


INDEX. 


Natural  gas,  cost  of  burning  with,  189 
objects,  manner  of  obtaining  tex- 
tures, low  reliefs  and  intaglios 
of,  534 

Nebuchadnezzar,  buried  palaces  of,  4 
name  of,  stamped  on  the  brick  in 

the  walls  of  Bagdad,  4 
Newark  Steel  Works,  fire  tests  at  the, 

77,  78 
New   England,   wages  of  carpenters 

and  bricklayers  in  1630,  in,  15 
New  Haven,  first  settlement  of  brick- 
makers  in,  15,  16 
New  Jersey  clay,  color  of,  82 

deposits,   average   depth 

of,  81 

supersession  of,  81 
clays,  plasticity  of,  83 
discovery     in,      of     making 

large  tiles,  526.  527 
fire-clays  and  associated  re- 
fractory  materials,    tables 
of  analyses  of,  68-76 
mufHe  terra-cotta  kilns  used 

in,  502,  503 
plastic  clay  belt  of,  61 
variety  and  extent  of  .clays 

in,  81 

New  Lisbon,  O.,  fire-clay  at,  47 
New  York,    annual   consumption   of 

brick  in.  20 

Architectural  Terra- Cotta Co., 
production 
of  a  pure 
white  terra- 
cotta by  the, 
471 

specimens  of 
the  work  of, 
471-478 

brick,  volume  of,  294 
Terra-Cotta  Lumber  Co.,  82 
New  Windsor  clay,  36 
Niedergesaess  patent   lubricating 

brick  die,  139-141 
Nile,  Delta  and  the  Fayoom,  6 

of  the,  1 
mud  of  the,  4 
Nineveh,  composition  of  stucco  used 

at,  8,  9 
Noah,  descendants  of  the  sons  of,  the 

first  potters,  2 
North  Devon,  England,  potter's  clay, 

analysis  of,  80 

Northwestern   Terra-Cotta   Co.,   Chi- 
cago, mufHe  kilns  of  the,  504,  505 
Num,  the  earliest  worker  in  pottery, 


OFF-BEARERS,  duties  of,  91 
Ohio  clays,  lithia  in,  31 
drain  tile  in,  453 
fire-brick  works,    hot   floors 

used  in,  356,357 
process  of  grinding  and  tem- 
pering fire  clay,  in  use  in, 
374,  375 
river,    brick   clay  along   the 

banks  of  the,  117,  118 
sewer-pipe   made    in,    quali- 
ties of,  42P,  430 
tile  works  in,  560 

Oil,  comparative  cost  of  burning 
brick  with,  and  other  fuels, 
195-197 

crude,   use  of,  for  burning  vitri- 
fied brick,  222 
suitable  for  the  die,  271 
Oligoclase,  32 

Olive-green  stain,  recipe  for,  415 
Omaha,  annual  consumption  of  brick 

in,  20 
Open  kiln,  setting  dry-clay  brick  in 

the,  245 
top  kiln,  183,  184 

burning  drain  tile  in  the, 

457,  459,  460 
setting  pressed  brick  in 

the,  265 
kilns,    proper    management 

of,  459,  460 
Opus  lateritium,  1 1 
reticulatum,  11 
Orange  stain,  recipe  for,  414 
Oregon,  brickmaking  in,  21 
Ornamental  and  pressed  brick,  man- 
ufacture of,  251-283 
brick,  277-283 

improvements  in  the  manu- 
facture of,  276 

manufacture  of,  by  the  stiff- 
mud  process,  279-281 
tiles,  511-541 
cost  of,  527 
dies  for,  524 
firing  of,  526 
in  the  brick  temple  of  Rame- 

ses  III.,  514,  515, 
manufacture  of,  522-526 
material  for,  522 
origin  of,  51 1 
rapid  advance  of  America  in 

the  production  of,  522 
stamping  machine  for,   523, 

524 

universal  occurrence  of,  51 1 , 
512 


INDEX. 


619 


Ornamental  work,  appliances  for,  279, 

280 

sand  or  grog  in,  281 
Orthoclase,  82 

Ottumwa  Paving  Brick  and  Construc- 
tion   Co.,    manufacture   of  paving 
brick  by  the,  233,  234 
Overhangers,  95 
Overhead  gearing,  347 

PALLETS,  94, 95, 157 

Pallet  system  of  drying,  151, 156,  j 

157 

Panel  re-press,  the,  282,  283 
Panels,  invention  for  the  production 

of,  596-598 

Pantile,  modifications  of,  543 
Pantiles,  554.  555 
first  use  of,  544 
modifications  of,  544,  545 
Party  walls,  salmon  brick  in,  11 
Pavements,  mosaic  plates  for,  inven-  i 

tion  for  manufacturing,  592-595 
Paving  blocks,  moulding  of,  220 

brick,    absorbent    conditions   of, 

221 

absorption  of  moisture  by,  21 
annealing  of,  228-230 
block  form  of,  214 
burning  of,  222-230 
clays,  38-45 
corners  of,  231 
demand  for,  21 
difference  in  the  cost  of  burn- 
ing, and  the  common  hard 
building  brick,  223 
drying  of,  221 ,  222 
fuel  for  burning,  226-228 
good,  requisites  for  a,  209 
methods  employed  by   vari- 
ous manufacturers  of,  230-  ! 
234 

most  popular  kind  of.  21 
moulding    and   pressing   of, 

219-221 

plant  construction,  210,211 
starting  and  managing  a, 

212-213 

preparation   of  clay  for,  218    • 
principle  involved  in  anneal- 
ing, 229,  2HO 
re-pressing  of,  220,  221 
size  of,  213.  214 
street,  manufacture  of,   209- 

234 
Pennsylvania,  brick  always  a  choice 

building  material  in,  16 
China  clays  in,  86 


Pennsylvania   fire-brick   works,    hot 

floors  used  in,  356,  357 
Penn,  William,   instructions   by,  for 

building  a  brick  house,  16 
Perfection  press,  of  C.  W.  Raymond, 

277-279 

Permanent  kiln  roofs,  303-305 
Perth  Amboy,  clay  at,  82 

Terra-CottaCo.,  plant  of  the, 

470 

Petroleum,  use  of,  as  a  fuel,  192-195 
Philadelphia,  annual  consumption  of 

brick  in,  20 
erection    of    Independence   Hall 

in,  17 

first  pressed  brick  made  in,  256 
"Great      Meeting       House       of 

Friends"  in,  17 
price    of    bricklayer's    labor    in 

1705,  in,  16 
production   per  day   of    pressed 

brick  in,  275 
superior  quality  of  pressed  brick 

produced  in,  275,  276 
£he  old  courthouse,  one  of  the 

oldest  brick  buildings  in,  17 
Phoenicians,  tiles  of  the,  518 
Pickering,  Thomas,  on  the  method  of 

making  fire-brick,  379,  380 
Pig  iron,  daily  output  of,  316 
Pike,  E.  M.,  on  drain  tile;  its  manu- 
facture and  use,  449-455 
on   the   difference    in    the 
cost   of  burning   paving 
brick   and   the  common 
hard  building  brick,  223 
Pillar-and-stall,  68 
Pillar  brick,  95 
Pithom,  excavations  made  on  the  site 

of,  5 

Pits,  contiguous,  advancing  the  dig- 
ging by,  62 

removal  of  water  from,  64,  65 

strengthening  the  walls  of,  64 

Pittsburgh,    annual    consumption  of 

brick  in,  20 
Place,    M.,   exploration   of   Assyrian 

buildings  by,  7,  8 
Plasticity.  54,  56.  57 

promotion  of,  by  weathering,  363 

Plates,    mosaic,   invention   of  Robert 

Eltzner  for  manufacturing,  592-595 

Pliny  on  the  brick  made  in  Greece, 

11 
Porcelain-makers,   formula   of   clays 

much  valued  by,  85 
Porosity,  water  of,  247 
Potash  in  clays,  31 


620 


INDEX. 


Potters,  meaning  of  the  term  kaolin 

when  used  by,  85 
the  first,  2 
Pottery  in  Egypt,  1 

invention  of,  by  the  gods,  1,  2 
the  earliest  worker  in,  1,2 
Press  Brick:  their  Manufacture  and 
Use,    paper   by  Wm.    Roberts   on, 
255-268 

Pressed  and  ornamental  brick,  manu- 
facture of,  251-283 
brick,  251-277 

best  machine  for,  270 
burning  of,  263-265,  273,  274 
difference  between  the,  and 

the  dry-clay  brick,  256 
difficulties  in  making,  by  ma- 
chinery, 261 ,  262 
drying  sheds  for,  252, 271 ,  272 
the  gluts  for,  before  re- 
pressing, 262,  263 
early  history  of,  256 
gluts  for,  254 
hand-made,  251 ,  252 
machines  used  in  making  the 

glut  for,  261 ,  262 
main   points    in    combining 

material  for,  258,  259 
mould  for,  251 ,  252 
moulding  the  gluts  for,  260- 

262 

one  of  the  first  qualities  re- 
quired in  a,  261 
original  meaning  of  the  term, 

256 

preparation  of  clay  for,269,270 
preserving  the  faces  of,  275 
pressing  of,  252 
production  of,  in  Trenton,  257 

per  day,  275 

pugging  process  for,  270 
quality  in,   of  first    import- 
ance, 276 

sanding  the  moulds  for,  270 
selecting  and  preparing  the 

clays  for,  257-260 
setting  of,  in  the  kiln,  252, 

253,  265,  266 
sorting  of,  274,  275 
stock  shed  for,  274 
superior  quality  of  Philadel- 
phia, 275,  276 
tempering  clay  for,  270 
testing  clay  for,  269 
time  required  to  burn  a  kiln 

of,  265,  266 

weathering  of  clay  for,  259, 
260 


"  Press-gang,"  composition  of  the,  251 

day's  work  for  the,  251 
Pressing     and    moulding    fire-brick, 

375-380 
paving-brick,  219- 

221 

Pressing  brick  which  are  to  be  enam- 
eled, 411,412 
Press,  screw,   for  making  tiles,  527, 

528 
sewer-pipe,  425,  426 

gang  for  running  a,  427 
used     at     the     Elliottsville 

works,  427 
Pressure,  capacity  of  sewer-pipe  for 

resisting,  445 

required  to  re-press  a  brick,  271 

to  find  the,  in  pounds  per  square 

inch  of  a  column  of  water,  445 

Pugging  process   for   pressed   brick, 

270 

Pug  mill,  capacity  of  a,  92 
double,  497 
double  geared,  135 
employed  in  England,  548 
granulating,  128-130 
spiral,  371 

tempering  clay  with  the,  89 
Pug  mills,  103-108,  133,  137 

motive  power  for,  107,  108 
Pulverizer,  use  of,  488 
Pulverizers,  dry-clay,  241-243 
Purington,   Chas.    S.,  on  the  use  of 

petroleum  as  a  fuel,  193-195 
Purington,  D.  V.,  on  the  use  of  oil 

for  burning  brick,  197-199 
Paving-Brick    Co.,    manufacture 

of  paving  brick  by  the,  233 
Pyramid  of  Laggara,  glazed  tiles  used 

in  the,  513,  514 

Pyramids,  adobes  used   in   the   con- 
struction of,  5 

Pyrites,  conversion  of,  into  metallic 
iron,  326 

QUARTZ,  resistance  of,  to  the  dis- 
solving action  of  slag,  316 
sand,  mixture  of,  with  clay,  366, 

367 
Quicksand  in  clay,  36 

RAILWAY  kiln,  the,  291 
Rake,  the,  103 
Rameses  II.,  3,  4 

III.,  ornamental  tile  in  the  brick 

temple  of,  514,515 
Raw  face,  92 

glazing  of  Dutch  tiles,  574-576 


INDEX. 


621 


Rawlinson,  Sir  H.,  on  the  brick  in 

the  walls  of  Bagdad,  4 
Raw  platting,  96 
Raymond,    C.    W.,    on    pressed   and 

ornamental  brick,  208-277 
perfection  press  of,  277-279 
tempering  wheel,  the,  109 
Red-brown  stain,  recipe  for,  414 
Reep,  J.  A.,  on  starting  and  manag- 
ing a  paving  brick  plant,  212-213 
Refractory      brickwork      of      blast- 
furnaces, and  its  preservation, 
313-326 
clays,  45-59 

material,  manufacture  of  a,  to  be 
used  in  a  given  locality,  309, 
310 

materials,  classification  of,  307 
wares,  most  important  constitu- 
ent of,  364 

Regenerative  kilns,  298-303 
Regenerator  blocks,  Siemens,  333 
Renwick,  James,   early   experiments  • 

in  the  use  of  terra-cotta  by,  470 
Re-press,  Eagle  Double  Mould,  283 
importance  and  care  of  the,  270, 

271 

Re-press,  panel,  the,  282,  283 
Re-pressing,  263 

days  to   "strike  out"  brick  for, 

268,  269 
Retorts,    drying   and    tempering   of, 

380 

Richardson  on  the  manufacture  of 
brick  by  the  drv-clay  process,  238- 
241 

Ridge  tiles,  modifications  of,  544,  545 
Ring  pits,  10S-114 

tempering  clay  in,  89 
River  process  and  Akron   process  of 
making  sewer-pipe,  difference 
in  the,  420.  427 

process  of  making  sewer-pipe,  425 

sewer-pipe,   qualities  of,   429,430 

Roberts,    Wm ,    paper   by    on    Press 

Brick:  their  Manufacture  and  Use, 

255-268 

Robinson,  F.  H.,  on  the  manufacture 
of  sewer- pipe  by  the  Delaware 
Terra  Cotta  Co.,  Wilmington,  Del., 
432-434 

Rolling  mill  tiles,  327 
Roman      architecture,      roofing-tiles 

used  in,  543 

statues  in  terra-cotta,  468 
tiles.  518,  519 

Romans  and  Greeks,  description   of 
roofing-tiles  used  by  the,  543 


Romans,  brick  first  burned  in  kilns  by 

the,  11 

construction  of  walls  by  the,  12 
conveyance  of  water  by  the,  in 

earthen  pipe,  450 
manufacture  of  brick  by  the,  in 

Germany  and  England,  12 
superior    quality    of    the    brick 

made  by  the,  10 

Rome,  destruction  of,  by  fire,  10 
height  of  buildings  in,  10 
introduction    of  roofing-tiles   in, 

543 

mosaic  manufacture  in,  590 
Roof,  construction  of  a,  for  tile,  547, 

548 

of  a  fire-brick  factory,  349,  350 
tile,  advantage  for  the,  546,  547 
with  tiles  of  various  shapes, 

546,  547 
tiling,  mode  of,  in  Munich,  571. 

572 
Roofing    material,    burned    clay   as, 

555-564 

division  of,  557 
requisites  of,  557 
tile,  black   554 
buff,  554 
in  France   557 
mass,  different  mixtures  for, 

569 

mass,  mixture  of  the  ingre- 
dients of,  569,  570 
red,  553 

saturated  with  water  and  al- 
lowed to  freeze,  577 
terra-cotta,  556 
tiles,  application  of  the  glaze  to, 

568 

barrow  for,  588,  589 
burning  of,  550,  551,  557 
colors  of,  553,  554 
constitution  of  glaze  for,  565, 

566 

flat,  moulding  of,  570 
form    and    size   of,    used   in 

Munich,  571,  572 
formation  of  moss  upon,  ot'5 
forms  of,  546,  547 
giving  the  set  or  curved  form 

to,  549 
glazed,   baking  together  of, 

in  burning  573,  574 
glazed,  scaling  of,  577 
glazed,  setting  of,  574 
glazes  for,  545,  546,  577-581 
glazing  of,  564-574 
historical  data  on,  542 


622 


INDEX. 


Roofing   tiles,    law  of   Edward   IV.,  | 

regulating  clay  for,  546 
machine  for  moulding,  from 

plastic  clay,  585-588 
Merrill's,  581-584 
manufacture  and  glazing  of, 

542-589 
of,  in  the  United  States, 

553 

most  important  glazes  for,  580 
moulding  of,  549 
new,  porosity  of,  564 
objections  to,  550 
older  form  of,  555 
patterns  of,  554 
plain  glazing  of,  572,  573 
price  of,  564 
process     of    manufacturing, 

548-555 

reasons  for  the   limited  nse 
of,   in   the   United   States, 
559,  560 
red,  experiments  in  making, 

571 

stacking  of,  550 
Roofs  of  the  middle  ages,  565 
Rospide,  A.,  on  roofing  tile  in  France, 

557 

Round  or  down-draft  kiln,  182,  183 
Royal  blue  stain,  recipe  for,  414 

Brick  Co.,   Bridgeport,  O.,  mode 
of  setting  fine   front  brick  by  I 
the,  272,  273 

QAGE-GREEN  stain,  recipe  for,  414 
vj    St.  Alban's  Abbey,  England,  old 

Roman  bricks  re-used  in,  12 
St.    Louis,    annual    consumption    of 

brick  in,  20 
fire-brick    factories,    method 

in  use  in,  376 

method     of    moulding    fire- 
brick in  the  district  of.  379 
Salmon-brick,  dry-clay,  237 

in  party  walls,  11 

Salt,  common,  effect  of,  upon  clay,  29 
common,  in  coal,  324 
glaze,  568 

glazing  with,  427,  428 
Sand,  function  of,  in  clay,  29 
influence  of,  on  glaze,  566 
moulding,  252 

or  grog  in  ornamental  work,  281 
Sands,  highly  valued  for  glazing  pur- 
poses, 566,  567 

Saw- dust,  mixing  clays  with,  449 
Scotland,  chief  building  material  in, 
14 


Scotland,  clay  used  for  terra-cotta  in, 

80 

Screen  press  for  making  tiles,  527,  528 
Screens,  61 
Seger,  Dr.  H.,  on  glazes  for  roofing 

tiles,  577-581 
Semi-plastic  brick,  248-250 

brick  press,  249,  250 
Setting  brick  in  the  kiln,  169-172 
fine  front  brick,  272,  273 
gang,  95 

duty  of  the,  96 

pressed  brick  in  the  kiln,  265-268 
the  green  brick  in  the  kiln,  95-97 
Settling  fires,  when  given,  100 
Sewer  pipe,  Akron,  character  of,  431 
process  of  making,  425 
reason  for  the  popularity 

of,  430 

barrow  for,  444 
branches,  434 

capacity  of,  for  resisting  pres- 
sure, 445 
Columbus,    reason     for    the 

the  popularity  of,  430 
glazing  of,  with  salt,  427,  428 
kilns  for,  434 
machine,    moulding    paving 

brick  by  a,  219 
manufacture  of,  425-445 

by  the  Dela- 
ware Terra 
Cotta  Co., 
Wilming- 
ton, Del., 
432-434 

material  for,  432,  433 
moulding  of,  43o 
press,  425,  426 

gang  for  running  a,  427 
used   at  the    Elliottsville 

works,  427 
rings,   machine   for   cutting, 

440-442 
river,  process  of  making,  425 

qualities  of,  429,  430 
salt-glazed,  vitrified,  diame- 
ter and  thickness  and  aver- 
age weight  per  foot  of,  444 
selection  of  clay  for,  425 
shapes  of,  445 
Standard  Cincinnati,  427 
traps,  434 
trimming  of,  434 
vitrified,  432 
pipes,  Akron,  worst  trouble  with, 

430 
fittings  which  go  with,  429 


INDEX. 


623 


Sgraffito  effects,  535 
Shale  clay,  analyses  of,  44 

clays,  mining  of,  214,  215 
Shea,  Mr.,  on  paving  brick  clay,  39 
on  the  size  of  paving  brick, 

213,  214 

Shed,  drying,  for  pressed  brick,  252 
improved  brick  drying,  153-156 
stock,  for  pressed  brick,  274 
Sheds,   drying   brick    in,   advantages 

of,  151 

Shingle  tiles,  554 
Shrinkage  in  fire-brick,  307 
limit  of,  247 

of  clay,  28 
linear,  of  clay,  28 
water  of,  of  clay,  28 
Shrinking  power  of  clay,  248 

water  of,  247 

Side-dumping  clay  car,  123,  124 
Siemens  heating  furnace  blocks,  320, 

333 
regenerator  blocks,  333 

tile  and  brick,  322 
steel  furnace,  plan  of,  331 
Silica,  analyses  of,  in  fire-clay,  54 
and  alumina,  relation  between,  54 
brick,  provisions  for  the  expan- 
sion of,  388 
rules  to  be  observed  by  the 

users  of,  888 

combined  and  free,  53,  54 
fire-brick,  38(5-394 
British,  38H 
burning  of,  390,  391 
carbon  fire-brick  for  furnaces, 
glass  pots,  gas  retorts  and 
fire-brick,  manufacture  of, 
306-401 

durability  of,  387 
expansion  of,  387,  388 
firms    in   the   United   States 
engaged    in   the  manufac- 
ture of,  392 

fractured  surface  of,  391 
preparation  of  the  lime  liquid 

for,  391,392 
re-presses  used   in   pressing, 

390 

scrupulous  care  in  the  manu- 
facture of,  391 

Silicates,  hydrated,  of  alumina,  con- 
stitution of,  54 

Silicious  brick,  tendency  to   expan- 
sion of,  308,  309 
Silver  gray  covering  mass,  575 
Sioux    City,    Iowa,    burning    paving 
brick  at,  224 


1  Sioux  City,  Iowa,  clay  at,  42,  43 
1  Six-stamp  mill,  495,  496 
Skintles,  95 
Slabs  and  steamboat  bridge-wall  tile, 

344 

i  Slasher,  the,  88 
Slate,  defects  of,  as  roofing  material. 

557,558 
prices  of,  564 
waste   brick,  enameling  of,  423, 

424 

Sleeves  for  stopper  rods,  334 
Sliding  tiles,  544 

Slipping  or  washing  clay   for   terra- 
cotta, 488 

Slips,  weight  of,  417 
Slop,  method  of  moulding,  94 
Smalts,  591 
Smith,  G.  B.,  on  the  use  of  gas  for 

burning  brick,  190,  191 
Snelus,  G.  J.,  analysis  of  "ganister" 

brick  by,  393 
Soak  pits^  126 
Soda  feldspar,  32 

fountains,  art -tile,  specimens  of, 
1     521 

in  clays,  31 
lime  feldspar,  32 
Soft  clay  machine,  moulding  paving 

brick  by  a,  219 
Soil,  cultivation  and  drainage  of,  449, 

450 

drained,  temperature  of,  451 
Sorting  fire-brick,  330-336 
pressed  brick,  274,  275 
South,  brickmaking  in  the,  20,  21 
drain-tile  in  the,  453 
Wales,  use  of  pulverized  brick  or 

grog  in,  281 
Spade,  gouge,  63 

Spain,  art  of  enameling  brick  intro- 
duced into,  402 
clay  from,  56 
fire-clays  from,  366 
use  of  sun  dried  brick  in,  9 
Specific  gravity  of  clays,  determina- 
tion of,  59 

Spiegel  cupola  brick,  336 
!  Square  top  kilns,  182 
:  Stains  for  enameled  brick,  prepara- 
tion of  418,  419 
recipes  for,  414,  415 
i  Stamping  machine    for    ornamental 

tile,  523,  524 
Star  brick,  339 

silica  brick,   analysis  of  a,  392, 

393 
Steam  dry  floors,  161-163 


624 


INDEX. 


Steam  dry  floor  used  in  England,  350- 

354 
drying,  455 

English  method,   objections 

to,  353 
floors,  350 
with,  500 
exhaust,  from  the  engine,  drying 

brick  with,  158-161,350 
increase     in    volume     of    water 

turned  into.  184 
shovel,  Barnhart,  118,  119 
shovels,  electric  power  for,  119 
wheel,  the,  125 
works    for    drvers,    construction 

of,  158-161 

Steel  furnace,  Siemens,  plan  of,  331 
Stephens   &   Co.,    specimens  of  the 

work  of,  471-478 
Stewart   &   Collins,    manufacture   of 

paving-brick  by,  231,  232 
Stiff-clay  brick  machine,  clay  for  the, 

34 

moulding  of,  137-139 
requirements  of,  137 
machine,  moulding  paving- 
brick  by  a,  219    ^ 
mud     process,    manufacture     of 
ornamental  brick  and  tiles  by 
the,  279-281 

Stock  shed  for  pressed  brick,  274 
Stone  separator,  494 

separator,  use  of,  488 
Stookey,  D.  W.,  on  burning  paving- 
brick,  225-230 
"Stoop  and  room,"  68 
Stopper  rod,  sleeves  for,  334 
Store  sheds,  157 
Storing,   weathering   and  elutriating 

fire-clay,  362-364 
Stourbridge  clay,  58,  395 
Stove  lining,  340 
Straight  courses,  95 
Street-paving  brick,  manufacture  of, 

209-234 

problem  to  be  solved 
in  the  production 
of,  38 
Stucco,  composition  of,  used  at  Nine 

veh,  8,  9 

used  in  California,  9 
Swindell's  patent  checker,  334 

"TABLE  showing  diameter  and  thick- 

1  ness      and      average 

weight     per    foot    of 

salt-glazed       vitrified 

sewer-pipe,  444 


Table  showing  the  value  and  proper- 
ties of  various  kinds 
of  coal,  181,  182 

Tables  of  analyses  of  fire-clays  and 
associated  refractory  materials,  68- 
76.. 

Table  tops,  invention  for  the  produc- 
tion of,  596-598 

Tablets,  Chaldean   and  Assyrian,  511 
Tailings  crusher,   improved,  217,  218 
Taylor,  James    machinery  for  terra- 
cotta manufacture  adopted 
by,  494 
on  the  use  of  terra-cotta  in 

architecture,  -179-482 
Teba  or  unburned  brick,  7 
Tempered  clay-brick,  drying  of,  150- 

153 

manufacture  of; 
including  de- 
scription of  most 
modern  machin- 
ery, 115-199 
Temperer,  hand,  work  of  the,  88 

tools  used  for  each,  108 
Temperers  for  ring  pits,  110 
Tempering  and  drying  refractorv  ar 

tides,  380-383 
grinding  fire-clay,  370- 

375 
preparing    clay,     125- 

130 

clay,  experiments  in,  127 
device,  Chambers,  202 
hand-method  of,  88 
hot  water,  127 
in  early  days,  125 
object  of,  89 
of  clay,  88,  89 
pug  mills,  494 
wheel,  old-fashioned,  126 

Raymond's,  109 

wheels,  difficulties  in   construct- 
ing and  operating,  109 
Temporary  kilns,  284-287 
Terra-cotta  and  brick  structure,  ideal, 

482 
architectural,      increase      in 

the  demand  for,  470 
manufacture  of,  468-510 
standard  for  texture  and 

hardness  of,  84 
as  a  building  material,  479 
as  a  substitute  for  stone,  479 
bas    reliefs     of    Luca    della 

Robbia  in,  468 
beauty  of,  469 
burning  of,  502  505 


INDEX. 


625 


Terra-cotta  clay,  80-85 
color  of,  482 
designs     for    execution    in, 

480,  481 
drying  a  piece  of  work  of, 

498.  499 
drying-boards  for,  497-499 

general  rules  for,  501 , 502 
early  use  of,  468 
Egyptian  and  Roman  statues 

in,  468 

endurance  of,  470 
evaporation  of  water  in  dry- 
ing, 483 

factory,   arrangement    of    a, 
482-186 

studio  of  a,  469 
first  application  of  the  name, 

468 

fuels  for,  505,  506 
kilns  for,  502-505 

improvement  in  the  con- 
struction of,  506-508 
lumber,  82 

method  of  finding  the  pro- 
portion of  crude  clay  and 
grit  for,  487 
mixing    clay   and    grit    for, 

488-491 

mixture  of  clays  for,  485, 486 
modeling  of,  508-510 
plant,  machines  required  for 

a,  494 

properties  of,  85 
proper  use  of,  480 
pure  .vhite,  471 
qualities  of,  468,  469 
roof  tile,  556 
slipping    or    washing    clays 

for,  488 
test  for,  84 
treatment  of  clays  for,  486- 

502 

use  of  for  decoration,  470 
value  of  clay  when  manufac- 
tured into,  493,  494 
vitrifying  ingredients  added 

to,  84 

Testing  fire-briok,  furnace  for,  52,  53 
Test  proofs,  422 
Texas,  brickmakiug  in,  21 

use  of  adobes  in,  9 
Thawing  clay,  127,  128 
Thebes,  illustrations  of  brickmaking 

on  the  tombs  of,  3 
Thothmes  III.,  stamp  of,  on  Egyptian 

brick,  7 
Tie  course,  95 

40 


Tiffany,  G.  S.,  on  the  manufacture  of 

vitrified  brick,  40,  41 
Tile  and  brick,  coke  oven,  325 

elevating  devices  for,  465 
machine,  improved  Cen- 
tennial, with  new  pat- 
tern   side-cut  delivery 
table,  143-145 
Siemens  regenerator,  322 
burning  of,  with  crude  oil,  191-199 
business,  capital  required  in,  562, 

563 

crushed,  mixing  clays  with,  449 
definition  of,  512,  555 
drain,  manufacture  of,  446-467 
drying  and  tempering  of,  380 
enameled,  513 
floor,  344 

gutter,  use  of  in  England.  544 
incised,  513 
indented,  512,  513 
inlaid,  512 

machine,  horizontal,  Dodd's  car- 
rier for,  465-467 
machines,  527,528 
makers,  the  oldest  known,  513 
making,  development  of.  in  the 

United  States,  519 
experience    and    knowledge 

required  in,  563 
revival  of,  519 
normal,  556 
painted,  513 
plain,  512 
printed,  512,  513 
qualities  of,  for  roofing,  563,  564 
rabbeted,  for  greenhouses,  flues, 

etc.,  344 
relief,  512,  513 
roof,  advantage  for  the,  546,  547 

for,  547,  548 
with  tiles  of  various  shapes, 

546,  547 

roofing,  in  France,  557 
truck,  589 

with  a  figure  in  relief,  plan  of  a, 
532,  533 

an  intaglio  figure,  plan  of  a, 
532,  533 
works,  articles  produced  in,  552 

in  the  United  States,  560 
Tiles,  advantages  of,  as  roofing  mate- 
rial, 557,  558 
ancient  glazed,  prevailing  colors 

in,  517 

ancient,  relics  of,  556 
and  blocks,  machine  for  making, 
344,  345 


626 


INDEX. 


Tiles  and  blocks  necessary  in  setting 
a  bench  of  fire-clay  re- 
torts in  gas  works,  343 
blocks  and  special  pieces,  manu- 

ture  of,  336-345 
boiler,  339 

care  in  dressing,  342,  343 
clay-dust,  having  surfaces  in  re- 
lief or  intaglio,  manufacture  of, 
532-536 
colored  glazed,  manufacture  of, 

in  Munich,  531,  532 
designs  in,  in  Assyria,  516 
dovetailed  grooves  on  the  backs 

of,  536 

Etruscan,  518 
families  of,  512 
glazed,    in  the  pyramid   of  La- 

garra,  513,  514 
of  the  Assyrians,  515,  516 
Babylonians,  515,  516 
or  enameled,  manufacture  of, 

in  France,  528-531 
glazed,  subdivision  of,  512,  513 
guiding  points  in  glazing,  528 
invention  for  the  production  of, 

596-598 
large,  art  of  making  a  New  Jersey 

discovery.  526, 527 
defect  in  making,  343,  344 
manufacture  of,  by  the  stiff-mud 

process,  279-281 
of  Chaldea,  516 
the  Jews,  518 

Phoenicians,  518 
ornamental,  511-541 
cost  of,  527 
dies  for,  524 
firing  of,  526 
in  the  brick  temple  of  Rame- 

ses  III.,  514,  515 
manufacture  of,  522-526 
material  for,  522 
origin  of,  511 
rapid  advance  of  America  in 

the  production  of,  522 
stamping  machine  for,  523, 

524 
universal  occurrence  of,  511, 

512 
patent,    discovery    for    making, 

527 
plain   roofing,  used  in  England, 

544 

rolling  mill,  327 
Roman,  518,  519 

roofing,  application  of  the  glaze 
to,  568 


Tiles,  roofing,  burning  of,  550,  551 
colors  of,  553,  554 
description   of,  used   by   the 

Romans  and  Greeks,  543 
forms  of,  546,  547 
giving  the  set  or  curved  form 

to,  549 

glazing  of,  564-574 
historical  data  of,  542 
law  of  Edward  IV.,  regulat- 
ing clay  for,  546 
manufacture  and  glazing  of, 

542-589 
of,  in  the  United  States, 

553 

marble,  543 
moulding  of,  549 
objections  to,  550 
older  form  of,  555 
patterns  of,  554 
price  of,  564 
process    of     manufacturing, 

548-555 

reasons  for  the  limited  use 
of,  in  the  United  States, 
559, 560 

stacking  of,  550 
used  in  Roman  architecture, 

543 

sliding,  544 

soaking  the  clay  for,  126 
unglazed,  subdivisions  of,  512 
use  of,  among  the  Greeks,  518 

as  a  circulating  medium  in 

Babylon,  517,  518 
wall,  fixing  of,  585,  536 
wet    clay   flooring,    manufacture 

of,  536-541 

white,  finer  glaze  for,  575 
Tileries,  London,  kilns  used  in  the, 

552,  553 
preparation  of  clay 

in,  552 

Toledo,  O.,  introduction  of  the  use 
of  natural  gas  for  burning  brick  in, 
190 

Tools  and  appliances  used  in  the  man- 
ufacture of  hand-made  brick, 
101-103 

used  for  each  temperer  108 
Trenton,  N.  J.,  careful  study  of  burn- 
ing brick  by  the  man- 
ufacturers of,  267 
commencement    of    the 
manufacture  of  pressed 
brick  in,  256 
cost  of  fuel  in,  268 
kilns  used  in,  267 


INDEX. 


627 


Trenton,  N.  J.,  production  of  pressed 

brick  in,  257 
time  occupied  in  burning 

a  kiln  in,  267 
Tuileries  in  Paris,  origin  of  name  of, 

546 

Tunnel  system  of  drying,  150 
Turley  &  Beyerly's  dry  floor,  354 
Turquoise  stain,  recipe  for,  414 
Tuyere,  Bessemer  converter,  334 
Two-roll  crusher,  130 

UNDER-DRAINS  for  agricultural 
purposes,  oldest  reference  to, 
450 

gearing,  347,  348 

Union   Mining   Co  ,    Mount  Savage, 
Md.,    handling    and    transporting 
fire-clay  by  the,  357-359 
United   States,    annual   consumption 
of   brick    in    the    leading 
cities  of  the,  20 

application  of  the  Hoffman 
kiln  to  the,  295,  296 

art  tile  works  in  the   522 

china  clays  in  the,  85,  86 

development  of  tile  making 
in  the,  519 

drawbacks  in  the  use  of  con- 
tinuous kilns  in  the,  292, 
293,  294 

drying  fire-brick  in  the,  381 

earliest  record  of  brick- 
makers  in  the,  15,  16 

fire  losses  in  the,  561 

firms  engaged  in  the  manu- 
facture of  silica  brick  in, 
392 

first  brick  building  in  the,  15 

increased  demand  for  build- 
ing material  in  the,  21 

introduction  of  terra-cotta 
into  the,  470 

manufacture  of  roofing-tiles 
in  the,  553 

method  of  making  fire-brick 
in  the,  o75 

objections  to  roofing-tile  in 
the,  550 

occurrence  of  superior  quali- 
ties of  fire-clays  in  the,  47 

patterns  of  roofing-tiles  em- 
ployed in  the,  554 

reasons  for  the  limited  use  of 
roofing  tiles  in  the,  559, 
560 

specific  knowledge  regarding 
the  details  of  the  manufac- 


ture   of   enameled    brick, 
lacking  in  the,  -J03 

United    States,    terra-cotta   manufac- 
tories in,  470,  471 
tile  works  in  the,  560 
use  of  silica  brick  in  the,  3S7 
when      brickwork       became 

common  in  the,  18 
Up  and  down  draft  kilns,  287-291 

-draft  kilns  for  burning  paving- 
brick,  226 
Upper  bench,  95 

VANDYKE  brown  stain,  recipe  for, 
414 

Van  T  wilier,  Wouter,  first  brick 
building  in  this  country  erected 
by,  15 

Virginia,  brick    brought   from   Eng- 
land to,  16 

good  brick-clay  found  in,  16 
Vitrified  brick,  manufacture  of,  40,41 
sewer-pipe,  432 

W^VGES  of  carpenters  and  brick- 
layers in  1630,  in  New  England, 
15 

Wagner,  John   G.,  on  preparing  and 
handling  clay  for  drain  tile,  447-449 
Wainscoting,  invention  for  the   pro- 
duction of,  596-598 
Wales,  manufacture  of  fire-brick  in, 

277 

Wall  ornamentation,  mosaic  plates 
for,  invention  for  manufacturing, 
592-595 

Wall  tiles,  fixing  of,  535,  536 
Washing  fire-clay,  370 

machine  for  fire-clay,  370 

or  slipping  clays  for  terra-cotta 

488 
Washington,  annual  consumption  of 

brick  in,  20 
brickmaking  in,  21 
monument,  the,  2 
Water,    conveyance    of,    in    earthen 

pipes  by  the  Romans,  450 
evaporation  of,  in  drying  terra- 
cotta. 483 
hoisting  of,  65 
hygroscopic,  in  clays,  46 
"  miner's  inch  "  of,  445 
of  pores,  of  clay,  28 
porosity,  247 
shrinkage,  28 
shrinking,  247 

pressure  per  square  inch  of  col- 
umns of,  445 


628 


INDEX. 


Water,  removal  of,  from  clay  pits,  64, 

65 

shrinkage,  limit  of,  246,  247 
smoke,  98.  184 

smoking  of  paving  brick,  222 
turned    into  steam,    increase   in ! 

volume  of,  184 
Weathering  of  clay,  259,  260 

storing  and  elutriating  fire-clay, 

362-364 

Weather  tiles,  544 
Weber,  Prof.,  method  of,  of  testing 

glazes,  578 

Wellsville  side-cut  table,  150 
Westerville,  O.,  clay  at,  44 
Weston,  Prof.,  W.,  analyses  of  Dinas  j 

"clay"  by,  389 

analyses    by,    of    North    Devon 
and   Dorsetshire  potter's  clay, 
80 
Wet  clay  flooring  tiles,  manufacture 

of,  536-541 
pan   method,  advantage  of,  372, 

373 

process  for  fire-clay,  372,  373 
the,  371 

Wheelbarrows,  175-178 
Wheeler,  duty  of  the,  90 
White  body,  424 


White  body,  recipes  for,  413 
covering  mass,  575 
glaze,  424 
Wilkes,  Peter,  screw-press  for  making 

tiles  made  by,  528 
Winding  drum,  friction,  120,  121 

gear  and   friction,    121- 

123 
drums,  359 

and  dump  cars,  120-125 
Wire  train,  English  system  of,  358 
Wolff  dryer,  455 
Woodbridge,  N.  J.,  clay  at,  82 
Wood,   impossibility  of  burning   all 
the    yearly   product    of    brick 
with,  182 

number  of  pounds  of  bituminous 
coal  equal  to  one  cord  of,  179, 
182 

Work  boxes,  invention  for  the  pro- 
duction of,  596-598 

VTELLOW  covering  mass,  575 
\      green  stain,  recipe  for,  414 
Young,   W.  Weston,   silica  fire-brick 
invented  by,  386 

iNC  in  clay,  30 


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Finishing  of  Fabrics,  Substitutes  for  Indigo,  Water-Proofing  of 
Materials,  Tests  and  Purification  of  Water,  Manufacture  of  Aniline 
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BLINN. — A  Practical  Workshop  Companion  for  Tin,  Sheet- 
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Containing  Rules  for  describing  various  kinds  of  Patterns  used  by 
Tin,  Sheet-Iron  and  Copper-plate  Workers;  Practical  Geometry; 
Mensuration  of  Surfaces  and  Solids ;  Tables  of  the  Weights  of 
Metals,  Lead-pipe,  etc.  ;*  Tables  of  Areas  and  Circumference* 
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BOOTH.— Marble  Worker's  Manual: 

Containing  Practical  Information  respecting  Marbles  in  general,  theii 
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Composition  and  Use  of  Artificial  Marble,  Stuccos,  Cements,  Receipts, 
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BOOTH  and  MORFIT. — The  Encyclopaedia  of  Chemistry, 

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Embracing  its  application  to  the  Arts,  Metallurgy,  Mineralogy, 
Geology,  Medicine  and  Pharmacy.  By  JAMES  C.  BOOTH,  Melter 
and  Refiner  in  the  United  States  Mint,  Professor  of  Applied  Chem- 
istry in  the  Franklin  Institute,  etc.,  assisted  by  CAMPBELL  MORFIT, 
author  of  "  Chemical  Manipulations,"  etc.  Seventh  Edition.  Com- 
plete in  one  volume,  royal  8vo.,  978  pages,  with  numerous  wood-cut* 
arid  other  illustrations  .......  ^S'S0* 

BRAM  WELL.— The  Wool  Carder's  Vade-Mecum, 

A  Complete  Manual  of  the  Art  of  Carding  Textile  Fabrics.  By  W* 
C.  BRAMWELL.  Third  Edition,  revised  and  enlarged.  Illustrated. 
Pp.  400.  I2mo.  .  .  .  •  i  •  •  •  •  $2.50 

BRAN  NT.— A   Practical   Treatise  on  Animal  and  Vegetable 

Fats  and  Oils  : 

Comprising  both  Fixed  and  Volatile  Oils,  their  Physical  and  Chemi- 
cal Properties  ana  Uses,  the  Manner  of  Extracting  and  Refining; 
them,  and  Practical  Rules  for  Testing  them ;  as  well  as  the  Manu- 
facture of  Artificial  Butter,  Lubricants,  including  Mineral  Lubricating 
Oils,  etc.,  and  on  Ozokerite.  Edited  chiefly  from  the  German  of 
DRS.  KARL  SCHAEDLER,  G.  W.  ASKINSON,  and  RICHARD  BRUNNERT 
with  Additions  and  Lists  of  American  Patents  relating  to  the  Extrac- 
tion, Rendering,  Refining,  Decomposing,  and  Bleaching  of  Fats  and 
Oils.  By  WILLIAM  T.  BRANNT.  Illustrated  by  244  engravings. 
739  pages.  Svo $12.50- 

BRANNT.— A  Practical  Treatise  on  the  Manufacture  of  Soap 

and  Candles  : 

Based  upon  the  most  Recent  Experiences  in  the  Practice  and  Science; 
comprising  the  Chemistry,  Raw  Materials,  Machinery,  and  Utensils 
and  Various  Processes  of  Manufacture,  including  a  great  variety  of 
formulas.  Edited  chiefly  from  the  German  of  Dr.  C.  Deite,  A. 
Engelhardt,  Dr.  C.  Schaedler  and  others;  with  additions  and  lists 
of  American  Patents  relating  to  these  subjects.  By  WM.  T.  BRANNT. 
Illustrated  by  163  engravings.  677  pages.  Svo.  .  .  $7.50 

BRANNT. — A  Practical  Treatise  on  the  Raw  Materials  and  the 
Distillation  and  Rectification  of  Alcohol,  and  the  Prepara- 
tion of  Alcoholic  Liquors,  Liqueurs,  Cordials,  Bitters,  etc.  : 
Edited  chiefly  from  the  German  of  Dr.  K.  Stammer,  Dr.  F.  Eisner, 
and  E.  Schubert.     By  WM.  T.  BRANNT.     Illustrated  by  thirty-one- 
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BRANNT— WAHL.— The  Techno- Chemical  Receipt  Book: 

Containing  several  thousand  Receipts  covering  the  latest,  most  im 
portant,  and  most  useful  discoveries  in  Chemical  Technology,  an(f 
their  Practical  Application  in  the  Arts  and  the  Industries.  Edited 
chiefly  from  the  German  of  Drs.  Winckler,  Eisner,  Heintze,  Mier 
zinski,  Jacobsen,  Koller,  and  Heinzerling,  with  additions  by  WM.  'I. 
BRANNT  and  WM.  H.  WAHL,  PH.  D.  Illustrated  by  78  engravings. 
I2mo.  495  pages  .  .  $2.00 

BROWN. — Five  Hundred  and  Seven  Mechanical  Movements: 
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Gearing,  Presses,  Horology  and  Miscellaneous  Machinery ;  and  in- 
cluding many  movements  never  before  published,  and  several  of 
which  have  only  recently  come  into  use.  By  HENRY  T.  BROWN, 
I2mo.  ..........  $1.00 

BUCKMASTER.— The  Elements  of  Mechanical  Physics  : 
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BULLOCK. — The  American  Cottage  Builder  : 

A  Series  of  Designs,  Plans  and  Specifications,  from  $200  to  $20,000, 
for  Homes  for  the  People ;  together  with  Warming,  Ventilation, 
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QULLOCK. — The  Rudiments  of  Architecture  and  Building: 
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BURGH. — Practical    Rules    for    the   Proportions   of     Modern 

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BYLES. — Sophisms    of    Free    Trade    and    Popular    Political 

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BOWMAN. — The  Structure  of  the  Wool  Fibre  in  its  Relation 

to  the  Use  of  Wool  for  Technical  Purposes : 
Being  the  substance,  with  additions,  of  Five  Lectures,  delivered  at 
ihe  request  of  the  Council,  to  the  members  of  the  Bradford  Technical 
College,  and  the  Society  of  Dyers  and  Colorists.  By  F.  H.  Bow- 
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BYRNE. — Hand-Book  for  the  Artisan,  Mechanic,  and  Engi- 
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BYRNE. — Pocket-Book  for  Railroad  and  Civil  Engineers : 
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work;  Levelling;  the  Calculation  of  Cuttings;  Embankments;  Earth- 
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BYRNE. — The  Practical  Metal-Worker's  Assistant :  * 

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and  Alloys;  Forging  ojf  Iron  and  Steel;  Hardening  and  Tempering; 
Melting  and  Mixing;  Casting  and  Founding ;  Works  in  Sheet  Metal; 
the  Processes  Dependent  on  the  Ductility  of  the  Metals;  Soldering; 
and  the  most  Improved  Processes  and  Tools  employed  by  Metal- 
workers. With  the  Application  of  the  Art  of  Electro-Metallurgy  to 
Manufacturing  Processes ;  collected  from  Original  Sources,  and  from 
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BYRNE.— The  Practical  Model  Calculator: 

For  the  Engineer,  Mechanic,  Manufacturer  of  Engine  Work,  NavaJ 
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600  pages $3-00 

CABINET  MAKER'S  ALBUM  OF  FURNITURE: 
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Illustrated  by  Forty-eight  Large  and  Beautifully  Engraved   Plates, 
Oblong,  8vo $2.00 

CALLINGHAM. — Sign  Writing  and  Glass  Embossing: 

A  Complete  Practical  Illustrated  Manual  of  the  Art.  By  JAMES 
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CAMPIN. — A  Practical  Treatise  on  Mechanical  Engineering: 
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Engines,  etc.  With  an  Appendix  on  the  Analysis  of  Iron  and  Iron 
Ores.  By  FRANCIS  CAMPIN,  C.  E.  To  which  a»e  added,  Observations 
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ARMSTRONG,  C.  E.,  and  JOHN  BOURNE.  Rules  for  Calculating  th« 
Change  Wheels  for  Screws  on  a  Turning  Lathe,  and  for  a  Wheel^ 
cutting  Machine.  By  J.  LA  NICCA.  Management  of  Steel,  Includ- 
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CAREY.— A  Memoir  of  Henry  C.  Carey. 

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CAREY.— The  Works  of  Henry  C.  Carey : 

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Manual  of  Social  Science.  Condensed  from  Carey's  "  Principles 
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The  Unity  of  Law :  As  Exhibited  in  the  Relations  of  Physical, 
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CLARK. — Tramways,  their  Construction  and  Working : 

Embracing  a  Comprehensive  History  of  the  System.  With  an  ex' 
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power, steam,  heated  water  and  compressed  air;  a  description  of  the 
varieties  of  Rolling  stock,  and  ample  details  of  cost  and  working  ex- 
penses. By  D.  KINNEAR  CLARK.  Illustrated  by  over  200  wood 
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COLBURN. — The  Locomotive  Engine  : 

Including  a  Description  of  its  Structure,  Rules  for  Estimating  its 
Capabilities,  and  Practical  Observations  on  its  Construction  and  Man- 
agement. By  ZERAH  COLBURN.  Illustrated.  I2mo.  .  $1.00 

COLLENS. — The  Eden  of  Labor;  or,  the  Christian  Utopia. 
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of  Charity,"  etc.     I2mo.     Paper  cover,  $  I.  oo;   Cloth          .         $1.25 

COOLEY. — A  Complete  Practical  Treatise  on  Perfumery : 
Being  a  Hand-book  of  Perfumes,  Cosmetics  and  other  Toilet  Articles, 
With   a  Comprehensive    Collection  of  Formulas.     By   ARNOLD  J< 
COOLEY.    i2mo $i.5& 

COOPER.— A  Treatise  on  the  use  of  Belting  for  the  Trans^ 

mission  of  Power. 

With  numerous  illustrations  of  approved  and  actual  methods  of  ar 
ranging  Main  Driving  and  Quarter  Twist  Belts,  and  of  Belt  Fasten 
ings.  Examples  and  Rules  in  great  number  for  exhibiting  and  cal- 
culating the  size  and  driving  power  of  Belts.  Plain,  Particular  and 
Practical  Directions  for  the  Treatment,  Care  and  Management  or 
Belts.  Descriptiont  of  many  varieties  of  Beltings,  together  with 
chapters  on  the  Transmission  of  Power  by  Ropes ;  by  Iron  and 
Wood  Frictional  Gearing  ;  on  the  Strength  of  Belting  Leather ;  and 
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CRAIK.— The  Practical  American  Millwright  and  MUler. 

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CREW. — A  Practical  Treatise  on  Petroleum : 

Comprising  its  Origin,  Geology,  Geographical  Distribution,  History, 
Chemistry,  Mining,  Technology,  Uses  and  Transportation.  Together 
with  a  Description  of  Gas  Wells,  the  Application  of  Gas  as  Fuel,  etc. 
By  BENJAMIN  J.  CREW.  With  an  Appendix  on  the  Product  and 
Exhaustion  of  the  Oil  Regions,  and  the  Geology  of  Natural  Gas  in 
Pennsylvania  and  New  York.  'By  CHARLES  A.  ASHBURNER,  M.  S.. 
Geologist  in  Charge  Pennsylvania  Survey,  Philadelphia.  Illustrated 
by  70  engravings.  8vo.  508  pages  ....  $7-S° 

iCROSS. — The  Cotton  Yarn  Spinner: 

Showing  how  the  Preparation  should  be  arranged  for  Different 
Counts  of  Yarns  by  a  System  more  uniform  than  has  hitherto  been 
practiced ;  by  having  a  Standard  Schedule  from  which  we  make  all 
our  Changes.  By  RICHARD  CROSS.  122  pp.  I2mo.  .  75 

CRISTIANL— A  Technical  Treatise  on  Soap  and  Candles: 
With  a   Glance  at  the   Industry  of  Fats  and  Oils.     By  R.  S.  CRIS 
TIANI,  Chemist.     Author  of  "  Perfumery  and  Kindred  Arts."     Illus- 
trated by  176  engravings.     581  pages,  8vo.         .         .         .        $15.00 
CRISTIANL— Perfumery  and  Kindred  Arts  : 

A  Comprehensive  Treatise  on  Perfumery,  containing  a  History  of 
Perfumes  from  the  remotest  ages  to  the  present  time.  A  complete  de- 
tailed description  of  the  various  Materials  and  Apparatus  used  in  the 
Perfumer's  Art,  with  thorough  Practical  Instruction  and  careful  For- 
mulae, and  advice  for  the  fabrication  of  all  known  preparations  of 
the  day.  By  R.  S.  CRISTIANI,  Consulting  Chemist  and  Perfumer, 
Philadelphia.  8vo $10.00 

COAL  AND  METAL  MINERS'  POCKET  BOOK: 

Of  Principles,  Rules,  Formulae,  and  Tables,  Specially  Compiled 
and  Prepared  for  the  Convenient  Use  of  Mine  Officials,  Mining  En^ 
gineers,  and  Students  preparing  themselves  for  Certificates  of  Compe- 
tency as  Mine  Inspectors  or  Mine  Foremen.  Revised  and  Enlarge^ 
edition.  Illustrated,  565  pages,  small  I2mo.,  cloth  .  $2.00 

Pocket  book  form,  flexible  leather  with  flap  .         .         $2.75 

IDAVIDSON. — A  Practical  Manual  of  House  Painting,  Grain* 

ing,  Marbling,  and  Sign- Writing : 

Containing  full  information  on  the  processes  of  House  Painting  i» 
Oil  and  Distemper,  the  Formation  of  Letters  and  Practice  of  Sign- 
Writing,  the  Principles  of  Decorative  Art,  a  Course  of  Elementary 
Drawing  for  House  Painters,  Writers,  etc.,  and  a  Collection  of  Useful 
Receipts.  With  nine  colored  illustrations  of  Woods  and  Marbles.^ 
and.  numerous  wood  engravings.  By  ELLIS  A.  DAVIDSON.  I2mo. 

$3.00 
DAVIES. — A   Treatise  on    Earthy  and   Other   Minerals   and 

Mining  : 

By  D.  C.  DAVIES,  F.  G.  S.,  Mining  Engineer,  etc.  Illustrated  by 
76  Engravings.  I2mo.  .......  $5-oc> 


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DAVIES.— A  Treatise  on  Metalliferous  Minerals  and  Mining: 
By  D.  C.  DAVIES,  F.  G.  S.r  Mining  Engineer,  Examiner  of  Mines. 
Quarries  and  Collieries.    Illustrated  by  148  engravings  of  Geological 
Formations,    Mining   Operations    and    Machinery,    drawn    from    the 
practice  of  all  parts  of  the  world.    2d  Edition,  I2mo.,  450  pages  $5.00 

DAVIES. — A  Treatise  on  Slate  and  Slate  Quarrying: 

Scientific,  Practical  and  Commercial.  By  D.  C.  DAVIES,  F.  G.  S., 
Mining  Engineer,  etc.  With  numerous  illustrations  and  folding 
plates.  lamo $2.00 

DAVIS. — A  Treatise  on  Steam-Boiler  Incrustation  and  Meth- 
ods for  Preventing  Corrosion  and  the  Formation  of  Scale  ; 
By  CHARLES  T.  DAVIS.     Illustrated  by  65  engravings.     8vo.    $1.50 

DAVIS. — The  Manufacture  of  Paper:' 

Being  a  Description  of  the  various  Processes  for  the  Fabrication, 
Coloring  and  Finishing  of  every  kind  of  Paper,  Including  the  Dif- 
ferent Raw  Materials  and  the  Methods  for  Determining  their  Values, 
the  Tools,  Machines  and  Practical  Details  connected  with  an  intelli- 
gent and  a  profitable  prosecution  of  the  art,  with  special  reference  to 
the  best  American  Practice.  To  which  are  added  a  History  of  Pa- 
per, complete  Lists  of  Paper-Making1  Materials,  List  of  American 
Machines,  Tools  and  Processes  used  in  treating  the  Raw  Materials, 
and  in  Making,  Coloring  and  Finishing  Paper.  By  CHARLES  T. 
DAVIS.  Illustrated  by  156  engravings.  608  pages,  8vo.  $6.00 

DAVIS.— The  Manufacture  of  Leather: 

Being  a  description  of  all  of  tl  Processes  for  the  Tanning,  Tawing, 
Currying,  Finishing  and  Dyeing  of  every  kind  of  Leather  ;  including 
the  various  Raw  Materials  and  the  Methods  for  Determining  their 
Values;  the  Tools,  Machines,  and  all  Details  of  Importance  con- 
nected with  an  Intelligent  and  Profitable  Prosecution  of  the  Art,  with 
Special  Reference  to  the  Best  American  Practice.  To  which  are 
added  Complete  Lists  of  all  American  Patents  for  Materials,  Pro- 
cesses, Tools,  and  Machines  for  Tanning,  Currying,  etc.  By  CHARLES 
THOMAS  DAVIS.  Illustrated  by  302  engravings  and  12  Samples  of 
Dyed  Leathers.  One  vol.,  8vo.,  824  pages  .  .  .  $25.00 

DAWIDOWSKY— BRANNT.— A  Practical  Treatise  on  the 
Raw  Materials  and  Fabrication  of  Glue,  Gelatine,  Gelatine 
Veneers  and  Foils,  Isinglass,  Cements,  Pastes,  Mucilages, 
etc. : 

Based  upon  Actual  Experience.  By  F.  DAWIDOWSKY,  Technical 
Chemist.  Translated  from  the  German,  with  extensive  additions, 
including  a  description  of  the  most  Recent  American  Processes,  by 
WILLIAM  T.  BRANNT,  Graduate  of  the  Royal  Agricultural  College 
of  Eldena,  Prussia.  35  Engravings.  I2mo.  .  .  .  $2.50 

DE  GRAFF.— The  Geometrical  Stair-Builders'  Guide : 
Being  a  Plain  Practical  System  of  Hand-Railing,  embracing  all  ita 
necessary  Details,  and  Geometrically  Illustrated  by  twenty-two  Steel 
Engravings ;  together  with  the  use  of  the  most  approved  principles 
of  Practical  Geometry.     By  SIMON  DE  GRAFF,  Architect.      4*0. 

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DE  KONINCK— DIETZ.— A  Practical  Manual  of  Chemical 

Analysis  and  Assaying : 

As  applied  to  the  Manufacture  of  Iron  from  its  Ores,  and  to  Cast  Iron, 
Wrought  Iron,  and  Steel,  as  found  in  Commerce.  By  L.  L.  DE 
KONINCK,  Dr.  Sc.,  and  E.  DIETZ,  Engineer.  Edited  with  Notes,  by 
ROBERT  MALLET,  F.  R.  S.,  F.  S.  G.,  M.  I.  C.  E.,  etc.  American 
Edition,  Edited  with  Notes  and  an  Appendix  on  Iron  Ores,  by  A.  A. 
FESQUET,  Chemist  and  Engineer.  I2mo.  .  .  .  $1.50 

DUNCAN.— Practical  Surveyor's  Guide: 

Containing  the  necessary  information  to  make  any  person  of  com* 
mon  capacity,  a  finished  land  surveyor  without  the  aid  of  a  teacher 
By  ANDREW  DUNCAN.  Revised.  72  engravings,  214  pp.  I2mo.  $1.50 

DUPLAIS. — A  Treatise  on  the   Manufacture  and  Distillation 

of  Alcoholic  Liquors : 

Comprising  Accurate  and  Complete  Details  in  Regard  to  Alcohol 
from  Wine,  Molasses,  Beets,  Grain,  Rice,  Potatoes,  Sorghum,  Aspho  • 
del,  Fruits,  etc. ;  with  the  Distillation  and  Rectification  of  Brandy, 
Whiskey,  Rum,  Gin,  Swiss  Absinthe,  etc.,  the  Preparation  of  Aro- 
matic Waters,  Volatile  Oils  or  Essences,  Sugars,  Syrups,  Aromatic 
Tinctures,  Liqueurs,  Cordial  Wines,  Effervescing  Wines,  etc.,  the 
Ageing  of  Brandy  and  the  improvement  of  Spirits,  with  Copious 
Directions  and  Tables  for  Testing  and  Reducing  Spirituous  Liquors, 
etc.,  etc.  Translated  and  Edited  from  the  French  of  MM.  DUPLAIS, 
Aine  et  Jeune.  By  M.  McKENNiE,  M.  D.  To  which  are  added  the 
United  States  Internal  Revenue  Regulations  for  the  Assessment  and 
Collection  of  Taxes  en  Distilled  Spirits.  Illustrated  by  fourteen 
folding  plates  and  several  wood  engravings.  743  pp.  8vo.  $10  oo 

DUSSAUCE.— Practical  Treatise  on  the  Fabrication  of  Matches, 

Gun  Cotton,  and  Fulminating  Powder. 
By  Professor  H.  DUSSAUCE.     I2mo.          .         .         .         .        $3  oo 

DYER  AND  COLOR-MAKER'S  COMPANION: 

Containing  upwards  of  two  hundred  Receipts  for  making  Colors,  on 
the  most  approved  principles,  for  all  the  various  styles  and  fabrics  now 
in  existence;  with  the  Scouring  Process,  and  plain  Directions  for 
Preparing,  Washing-off,  and  Finishing  the  Goods.  I2mo.  $1.00 

EDWARDS. — A  Catechism  of  the  Marine  Steam-Engine, 
For  the  use  of  Engineers,  Firemen,  and  Mechanics.  A  Practical 
Work  for  Practical  Men.  By  EMORY  EDWARDS,  Mechanical  Engi- 
neer. Illustrated  by  sixty-three  Engravings,  including  examples  of 
the  most  modern  Engines.  Third  edition,  thoroughly  revised,  with 
much  additional  matter.  12 mo.  414  pages  .  .  .  $2  oo 

EDWARDS. — Modern  American  Locomotive  Engines, 

Their  Design,  Construction  and  Management.  By  EMORY  EDWARDS* 
Illustrated  I2mo $2.00 

EDWARDS. — The  American  Steam  Engineer: 

Theoretical  and  Practical,  with  examples  of  the  latest  and  most  ap- 
proved American  practice  in  the  design  and  construction  of  Steam 
Engines  and  Boilers.  For  the  use  of  engineers,  machinists,  boiler- 
makers,  and  engineering  students.  By  EMORY  EDWARDS.  Fully 
illustrated,  419  pages.  12010.  ....  $2.50 


12         HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 

EDWARDS.— Modern  American  Marine  Engines,  Boilers,  an4 

Screw  Propellers, 

Their  Design  and  Construction.  Showing  the  Present  Practice  of 
the  most  Eminent  Engineers  and  Marine  Engine  Builders  in  the 
United  States.  Illustrated  by  30  large  and  elaborate  plates.  4*0.  $5.00 
CD  WARDS.— The  Practical  Steam  Engineer's  £uide 
In  the  Design,  Construction,  and  Management  of  American  Stationary, 
Portable,  and  Steam  Fire- Engines,  Steam  Pumps,  Boilers,  Injector^ 
Governors,  Indicators,  Pistons  and  Rings,  Safety  Valves  and  Steanv 
Gauges.  For  the  use  of  Engineers,  Firemen,  and  Steam  Users.  B> 
EMORY  EDWARDS.  Illustrated  by  119  engravings.  4.20  pages. 
I2mo $2  50 

EISSLER.— The  Metallurgy  of  Gold  : 

A  Practical  Treatise  on  the  Metallurgical  Treatment  of  Gold-Bear- 
ing  Ores,  including  the  Processes  of  Concentration  and  Chlorination, 
and  the  Assaying,  Melting,  and  Refining  of  Gold.  By  M.  EISSLER. 
With  132  Illustrations.  I2mo $5.00 

EISSLER.— The  Metallurgy  of  Silver  : 

A  Practical  Treatise  on  the  Amalgamation,  Roasting,  and  Lixiviation 
of  Silver  Ores,  including  the  Assaying,  Melting,  and  Refining  of 
Silver  Bullion.  By  M.  EISSLER.  124  Illustrations.  336  pp. 
I2mo ^ $4.25 

ELDER. — Conversations  on  the  Principal  Subjects  of  Political 

Economy. 
By  DR.  WILLIAM  ELDER.     8vo $2.50 

ELDER. — Questions  of  the  Day, 

Economic  and  Social.     By  DR.  WILLIAM  ELDER.     8vo.     .      $3.00 

ERNI.— Mineralogy  Simplified. 

Easy  Methods  of  Determining  and  Classifying  Minerals,  including 
Ores,  by  means  of  the  Blowpipe,  and  by  Humid  Chemical  Analysis, 
based  on  Professor  von  Kobell's  Tables  for  the  Determination  of 
Minerals,  with  an  Introduction  to  Modern  Chemistry.  By  HENRY 
ERNI,  A.M.,  M.D.,  Professor  of  Chemistry.  Second  Edition,  rewritten, 
enlarged  and  improved.  I2mo.  .....  $3  °° 

FAIRBAIRN.— The  Principles  of  Mechanism  and  Machinery 

of  Transmission  • 

Comprising  the  Principles  of  Mechanism,  \Vheels,  and  Pullevs4 
Strength  and  Proportions  of  Shafts,  Coupling  of  Shafts,  and  Engag- 
ing  and  Disengaging  Gear.  By  SIR  WILLIAM  FAIRBAIRN,  Bart 
C.  E.  Beautifully  illustrated  by  over  ,150  wood-cuts.  In  one 
volume.  I2mo $2.50 

FLEMING.— Narrow  Gattge  Railways  in  America. 
A  Sketch  of  their  Rise,  Progress,  and   Success.     Valuable  Statistics 
as  to  Grades,  Curves,  Weight  of  Rail,  Locomotives,  Cars,  etc.     By 
HOWARD  FLEMING.     Illustrated,  8vo.      .         .         .        .        $i  oo 

FORSYTH.— Book   of   Designs  for  Headstones,   Mural,   and 

other  Monuments: 

Containing  78  Designs.  By  JAMES  FORSYTH.  With  an  Introduction 
by  CHARLES  BOUTELL,  M.  A.  4  to.,  cloth  .  $&  oo 


HENRY    CAREY   BAIRD   &   CO.'S   CATALOGUE. 


•FRANKEL— HUTTER.— A  Practical  Treatise  on  the  Manu* 

facture  of  Starch,  Glucose,  Starch-Sugar,  and  Dextrine: 
Based  on  the  German  of  LADISLAUS  VON  WAGNER,  Professor  in  the 
Royal  Technical  High  School,  Buda-Pest,  Hungary,  and  other 
authorities.  By  JULIUS  FRANKEL,  Graduate  of  the  Polytechnic 
School  of  Hanover.  Edited  by  ROBERT  HUTTER,  Chemist,  Practical 
Manufacturer  of  Starch-Sugar.  Illustrated  by  58  engravings,  cover- 
ing every  branch  of  the  subject,  including  examples  of  the  most 
Recent  and  Best  American  Machinery.  8vo.,  344  pp.  .  $3.50 

GARDNER. — The  Painter's  Encyclopaedia: 

Containing  Definitions  of  all  Important  Words  in  the  Art  of  Plain 
and  Artistic  Painting,  with  Details  of  Practice  in  Coach,  Carriage, 
Railway  Car,  House,  Sign,  and  Ornamental  Painting,  including 
Graining,  Marbling,  Staining,  Varnishing,  Polishing,  Lettering, 
Stenciling,  Gilding,  Bronzing,  etc.  By  FRANKLIN  B.  GARDNER. 
158  Illustrations.  I2mo.  427  pp.  .....  $2.00 

GARDNER.— Everybody's  Paint  Book: 

A  Complete  Guide  to  the  Art  of  Outdoor  and  Indoor  Painting,  De- 
signed for  the  Special  Use  of  those  who  wish  to  do  their  own  work, 
and  consisting  of  Practical  Lessons  in  Plain  Painting,  Varnishing, 
Polishing,  Staining,  Paper  Hanging,  Kalsomining,  etc.,  as  well  as 
Directions  for  Renovating  Furniture,  and  Hints  on  Artistic  Work  for 
Home  Decoration.  38  Illustrations.  I2mo.,  183  pp.  .  $1.00 

SEE.— The  Goldsmith's  Handbook : 

Containing  full  instructions  for  the  Alloying  and  Working  of  Gold, 
including  the  Art  of  Alloying,  Melting,  Reducing,  Coloring,  Col- 
lecting,  and  Refining;  the  Processes  of  Manipulation,  Recovery  of 
Waste;  Chemical  and  Physical  Properties  of  Gold;  with  a  New 
System  of  Mixing  its  Alloys ;  Solders,  Enamels,  and  other  Useful 
Rules  and  Recipes.  By  GEORGE  E.  GEE.  I2mo.  0  .  $!-75 

GEE.— The  Silversmith's  Handbook  : 

Containing  full  instructions  for  the  Alloying  and  Working  of  Silver$ 
including  the  different  modes  of  Refining  and  Melting  the  Metal;  its 
Solders ;  the  Preparation  of  Imitation  Alloys ;  Methods  of  Manipula- 
tion; Prevention  of  Waste  ;  Instructions  for  Improving  and  Finishing 
the  Surface  of  the  Work ;  together  with  other  Useful  Information  and 
Memoranda.  By  GEORGE  E.  GEE.  Illustrated.  i2mo.  $i'75 

GOTHIC  ALBUM  FOR  CABINET-MAKERS: 

Designs  for  Gothic  Furniture.     Twenty-three  plates.     Oblong  $2.00 

GRANT.— A  Handbook  on  the  Teeth  of  Gears  : 
Their  Curves,  Properties,  and  Practical  Construction.     By  GEORGE 
B.  GRANT.     Illustrated.     Third  Edition,  enlarged.     8vo.          $I.OQ 

GREENWOOD.— Steel  and  Iron: 

Comprising  the  Practice  and  Theory  of  the  Several  Methods  Pur- 
sued in  their  Manufacture,  and  of  their  Treatment  in  the  Rolling- 
Mills,  the  Forge,  and  the  Foundry.  By  WILLIAM  HENRY  GREEN- 
WOOD, F.  C.  S.  With  97  Diagrams,  536  pages.  I2mo.  $2.00 


14       HENRY   CAREY   BAIRD   &   CO.'S  CATALOGUE. 


GREGORY. — Mathematics  for  Practical  Men : 

Adapted  to  the  Pursuits  of  Surveyors,  Architects,  Mechanics,  and 
Civil  Engineers.  By  OLINTHUS  GREGORY.  8vo.,  plates  $3.00 

GRISWOLD. — Railroad  Engineer's  Pocket  Companion  for  the 

Field : 

Comprising  Rules  for  Calculating  Deflection  Distances  and  Angles, 
Tangential  Distances  and  Angles,  and  all  Necessary  Tables  for  En 
gineers;  also  the  Art  of  Levelling  from  Preliminary  Survey  to  the 
Construction  of  Railroads,  intended  Expressly  for  the  Young  En- 
gineer, together  with  Numerous  Valuable  Rules  and  Examples.  By 
W.  GRISWOLU.  i2mo.,  tucks $1-75 

GRUNER. — Studies  of  Blast  Furnace  Phenomena: 

By  M.  L.  GRUNER,  President  of  the  General  Council  of  Mines  oS 
France,  and  lately  Professor  of  Metallurgy  at  the  Ecole  des  Mines. 
Translated,  with  the  author's  sanction,  with  an  appendix,  by  L.  D. 
B.  GORDON,  F.  R.  S.  E.,  F.  G.  S.  8vo.  .  .  .  $2.50 

Hand-Book  of  Useful  Tables  for  the  Lumberman,  Farmer  and 

Mechanic: 

Containing  Accurate  Tables  of  Logs  Reduced  to  Inch  Board  Meas, 
ure,  Plank,  Scantling  and  Timber  Measure ;  Wages  and  Rent,  by 
Week  or  Month;  Capacity  of  Granaries,  Bins  and  Cisterns;  Land 
Measure,  Interest  Tables,  with  Directions  for  Finding  the  Interest  on 
any  sum  at  4,  5,  6,  7  and  8  per  cent.,  and  many  other  Useful  Tables. 
32  mo.,  boards.  ,  1 86  pages  ......  .25 

HASERICK.— The  Secrets  of  the  Art  of  Dyeing  Wool,  Cotton, 

and  Linen, 

Including  Bleaching  and  Coloring  Wool  and  Cotton  Hosiery  and 
Random  Yarns.  A  Treatise  based  on  Economy  and  Practice.  By 
E.  C.  HASERICK.  Illustrated  by  323  Dyed  Patterns  of  the  Yami 
or  fabrics.  8vo $7-5O 

HATS  AND  FELTING: 

A  Practical  Treatise  on  their  Manufacture.  By  a  Practical  Hatter, 
Illustrated  by  Drawings  of  Machinery,  etc.  8vo.  .  .  $I.2£ 

HOFFER. — A    Practical   Treatise   on    Caoutchouc  and   Gutta 

Percha, 

Comprising  the  Properties  of  the  Raw  Materials,  and  the  manner  or' 
Mixing  and  Working  them ;  with  the  Fabrication  of  Vulcanized  and 
Hard  Rubbers,  Caoutchouc  and  Gutta  Percha  Compositions,  Water- 
proof Substances,  Elastic  Tissues,  the  Utilization  of  Waste,  etc.,  etc, 
From  the  German  of  RAIMUND  HOFFER.  By  W.  T.  BRANNT. 
Illustrated  I2mo.  .  $2.50 

HAUPT. — Street  Railway  Motors  : 

With  Descriptions  and  Cost  of  Plants  and  Operation  of  the  Various 
Systems  now  in  Use.  I2mo.  $1-75 


HENRY   CAREY   BAIRD   &   CO.'S   CATALOGUE. 


HAUPT— RHAWN.— A  Move  for  Better  Roads: 

Essays  on  Road-making  and  Maintenance  and  Road  Laws,  for 
which  Prizes  or  Honorable  Mention  were  Awarded  through  the 
University  of  Pennsylvania  by  a  Committee  of  Citizens  of  Philadel- 
phia, with  a  Synopsis  of  other  Contributions  and  a  Review  by  the 
Secretary,  LEWIS  M.  HAUPT,  A.  M.,  C.  E.;  also  an  Introduction  by 
WILLIAM  H.  RHAWN,  Chairman  of  the  Committee.  319  pages. 
8vo $2.00 

HUGHES.— American  Miller  and  Millwright's  Assistant: 
By  WILLIAM  CARTER  HUGHES.  .  i2mo $1.50 

HULME. — Worked  Examination  Questions  in  Plane  Geomet- 
rical Drawing  : 

For  the  Use  of  Candidates  for  the  Royal  Military  Academy,  Wool- 
wich; the  Royal  Military  College,  Sandhurst ;  the  Indian  Civil  En- 
gineering College,  Cooper's  Hill  ;  Indian  Public  Works  and  Tele- 
graph Departments ;  Royal  Marine  Light  Infantry  ;  the  Oxford  and 
Cambridge  Local  Examinations,  etc.  By  F.  EDWARD  HULME,  F.  L. 
S.,  F.  S.  A.,  Art-Master  Marlborough  College.  Illustrated  by  300 
examples.  Small  quarto °  $2.50. 

JERVIS.— Railroad  Property: 

A  Treatise  on  the  Construction  ami  Management  of  Railways; 
designed  to  afford  useful  knowledge,  in  the  popular  style,  to  the 
holders  of  this  class  of  property  ;  as  well  as  Railway  Managers,  Offi- 
cers, and  Agents.  By  JOHN  B.  JERVIS,  late  Civil  Engineer  of  the 
Hudson  River  Railroad,  Croton  Aqueduct,  etc.  i2mo.,  cloth  $2.oc 

KEENE.— A  Hand-Book  of  Practical  Gauging: 

For  the  Use  of.  Beginners,  to  which  is  added  a  Chapter  on  Distilla- 
tion, describing  the  process  in  operation  at  the  Custom-House  fof 
ascertaining  the  Strength  of  Wines.  By  JAMES  B.  KEENE,  of  H.  M. 
Customs.  8vo. $1.25 

KELLEY.— Speeches,  Addresses,  and  Letters  on  Industrial  and 

Financial  Questions : 
By  HON.  WILLIAM  D.  KELLEY,  M.  C.     544  pages,  8vo.  .        $2.50 

KELLOGG.— A  New  JMonetary  System  : 

The  only  means  of  Securing  the  respective  Rights  of  Labor  and 
Property,  and  of  Protecting  the  Public  from  Financial  Revulsions.) 
By  EDWARD  KELLOGG.  Revised  from  his  work  on  "Labor  and 
other  Capital."  With  numerous  additions  from  his  mnnuscript. 
Edited  by  MARY  KELLOGG  PUTNAM.  Fifth  edition.  To  which  i* 
added  a  Biographical  Sketch  of  the  Author.  One  volume,  I2mo. 

Paper  cover       .         . |l.oo 

Bound  in  cloth  .  *-25 

KEMLO.— Watch-Repairer's  Hand-Book : 
Being  a  Complete  Guide  to  the  Young  Beginner,  in  Taking  Apart, 
Putting  Together,  and  Thoroughly  Cleaning  the  English  Lever  and 
other  Foreign  Watches,  and  all  American  Watches.     By  F.  KEMLO, 
Practical  Watchmaker.     With  Illustrations.     I2mo,  .         $1.25 


16  HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 

KENTISH.— A  Treatise  on  a  Box  of  Instruments, 

And  the  Slide  Rule ;  with  the  Theory  of  Trigonometry  and  Logs 
rit.hms,  including  Practical  Geometry,  Surveying,  Measuring  of  Tim- 
her,  Cask  and  Malt  Gauging,  Heights,  and  Distances.  By  THOMA* 
KENTISH.  In  one  volume.  I2mo.  ....  $1.25 

KERL.— The  Assayer's  Manual: 

An  Abridged  Treatise  on  the  Docimastic  Examination  of  Ores,  and 
Furnace  and  other  Artificial  Products.  By  BRUNO  KERL,  Professor 
in  the  Royal  School  of  Mines.  Translated  from  the  German  by 
WILLIAM  T.  BRANNT.  Second^American  edition,  edited  with  Ex- 
tensive Additions  by  F.  LYNWOOD  GARRISON,  Member  of  the 
American  Institute  of  Mining  Engineers,  etc.  Illustrated  by  87  en- 
gravings. 8vo #3.00 

KICK.— Flour  Manufacture . 

A  Treatise  on  Milling  Science  and  Practice.  By  FREDERICK  KICK 
Imperial  Regierungsrath,  Professor  of  Mechanical  Technology  in  tht. 
imperial  German  Polytechnic  Institute,  Prague.  Translated  from 
the  second  enlarged  and  revised  edition  with  supplement  by  H.  H. 
P.  POWLES,  Assoc.  Memb.  Institution  of  Civil  Engineers.  Illustrated 
with  28  Plates,  and  167  Wood-cuts.  367  pages.  8vo.  .  $10.00 

KINGZETT.— The   History,   Products,  and   Processes  of  the 

Alkali  Trade : 

Including  the  most  Recent  Improvements.  By  CHARLES  TnoMAb 
KINGZETT,  Consulting  Chemist.  With  23  illustrations.  8vo.  $2.50 

KIRK. — The  Founding  of  Metals  : 

A  Practical  Treatise  on  the  Melting  of  Iron,  with  a  Description  of  the 
Founding  of  Alloys;  also,  of  all  the  Metals  and  Mineral  Substances 

,  used  in  the  Art  of  Founding.  Collected  from  original  sources.  B> 
EDWARD  KIRK,  Practical  Foundryman  and  Chemist.  Illustrated. 
Third  edition.  8vo $2.50 

LANDRIN.— A  Treatise  on  Steel: 

Comprising  its  Theory,  Metallurgy,  Properties,  Practical  Working, 
and  Use.  By  M.  H.  C.  LANDRIN,  JR.,  Civil  Engineer.  Translated 
from  the  French,  with  Notes,  by  A.  A.  FESQUET,  Chemist  and  En 
gineer.  With  an  Appendix  on  the  Bessemer  and  the  Martin  Pro- 
reuses  for  Manufacturing  Steel,  from  the  Report  of  Abram  S.  Hewitt 
United  States  Commissioner  to  the  Universal  Exposition,  Paris,  1867, 
I2mo $3-00 

LANGBEIN.— A  Complete  Treatise  on  the  Electro-Deposition 

of  Metals  : 

Translated  from  the  German,  with  Additions,  by  WM.  T.  BRANNT, 
125  illustrations.  8vo. $4.00 

LARDNER.— The  Steam-Engine  : 

For  the  Use  of  Beginners.     Illustrated.     I2mo.    •         •         •         75 

LEHNER.— The  Manufacture  of  Ink: 

Comprising  the  Raw  Materials,  and  the  Preparation  df  Waiting, 
Copying  and  Hekiograph  Inks,  Safety  Inks,  Ink  Extracts  and  Pow- 
ders, etc.  Translated  from  the  German  of  SIGMUND  LEHNER,  wjth 
additions  by  WILLIAM  T.  BRANNT.  Illustrated.  I2mo.  $2.00 


HENRY   CARE\?    BAIRD   &   CO.'S   CATALOGUE.        17 

LARKIN. — The  Practical  Brass  and  Iron  Founder's  Guide: 
A  Concise  Treatise  on  Brass  Founding,  Moulding,  the  Metals  and 
their  Alloys,  etc. ;  to  which  are  added  Recent  Improvements  in  the 
Manufacture  of  Iron,  Steel  by  the  Bessemer  Process,  etc.,  etc.  By 
TAMES  LARKIN,  late  Conductor  of  the  Brass  Foundry  Department  m 
Reany,  Neafie  &  Co.'s  Penn  Works,  Philadelphia.  New  edition, 
revised,  with  extensive  additions.  121110.  .  .  .  $2.50 

LEROUX.— A    Practical     Treatise    on    the    Manufacture    of 

Worsteds  and  Carded  Yarns  : 

Comprising  Practical  Mechanics,  with  Rules  and  Calculations  applied 
to  Spinning;  Sorting,  Cleaning,  and  Scouring  Wools;  the  English 
and  French  Methods  of  Combing,  Drawing,  and  Spinning  Worsteds, 
and  Manufacturing  Carded  Yarns.  Translated  from  the  French  of 
CHARLES  LEROUX,  Mechanical  Engineer  and  Superintendent  of  a 
Spinning-Mill,  by  HORATIO  PAINE,  M.  D.,  and  A.  A.  FESQUET, 
Chemist  and  Engineer.  Illustrated  by  twelve  large  Plates.  To  which 
is  added  an  Appendix,  containing  Extracts  from  the  Reports  of  the 
International  Jury,  and  of  the  Artisans  selected  by  the  Committee 
appointed  by  the  Council  of  the  Society  of  Arts,  London,  on  Woolen 
and  Worsted  Machinery  and  Fabrics,  as  exhibited  in  the  Paris  Uni- 
versal Exposition,  1867.  8vo.  .....  $5.00 

LEFFEL.— The  Construction  of  Mill-Dams  : 
Comprising  also  the  Building  of  Race  and  Reservoir  Embankments 
and   Head-Gates,  the   Measurement  of  Streams,  Gauging  of  Water 
Supply,  etc.     By  JAMES  LEFFEL  &  Co.    Illustrated  by  58  engravings. 
8vo. $2.50 

LESLIE.— Complete  Cookery: 

Directions  for  Cookery  in  its  Various  Branches.  By  Miss  LESLIE. 
Sixtieth  thousand.  Thoroughly  revised,  with  the  addition  of  New 
Receipts.  I2mo.  . $1.50 

LE  VAN. — The  Steam  Engine  and  the  Indicator : 

Their  Origin  and  Progressive  Development;  including  the  Most 
Recent  Examples  of  Steam  and  Gas  Motors,  together  with  the  Indi- 
cator, its  Principles,  its  Utility,  and  its  Application.  By  WILLIAM 
BARNET  LE  VAN.  Illustrated  by  205  Engravings,  chiefly  of  Indi- 
cator-Cards. 469  pp.  8vo.  ......  $4.00 

LIEBER.— Assayer's  Guide  : 

Or,  Practical  Directions  to  Assayers,  Miners,  and  Smelters,  for  the 
Tests  and  Assays,  by  Heat  and  by  Wet  Processes,  for  the  Ores  of  all 
the  principal  Metals,  of  Gold  and  Silver  Coins  and  Alloys,  and  of 
Coal,  etc.  By  OSCAR  M.  LIEBER.  Revised.  283  pp.  I2mo.  $1.50 

IxDckwood's  Dictionary  of  Terms  : 

Used  in  the  Practice  of  Mechanical  Engineering,  embracing  those 
Current  in  the  Drawing  Office,  Pattern  Shop,  Foundry,  Fitting,  Turn-^ 
Ing,  Smith's  and  Boiler  Shops,  etc.,  etc.,  comprising  upwards  of  Six' 
Thousand  Definitions.  Edited  by  a  Foreman  Pattern  Maker,  author 
of  "  Pattern  Making."  417  pp.  I2mo.  .  .  .  $3.00 


i8         HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


LUKIN.— Amongst  Machines: 

Embracing  Descriptions  of  the  various  Mechanical  Appliances  used 
in  the  Manufacture  of  Wood,  Metal,  and  other  Substances.  J2mo. 

fas 

LUKIN.— The  Boy  Engineers : 
What  They  Did,  and  How  They  Did  It.     With  30  plates.    I8mo. 

11.75 

LUKIN.— The  Young  Mechanic  c 

Practical  Carpentry.  Containing  Directions  for  the  Use  of  all  kinds 
of  Tools,  and  for  Construction  of  Steam- Engines  and  Mechanical 
Models,  including  the  Art  of  Turning  in  Wood  and  Metal.  By  JOHN; 
LUKIN,  Author  of  "The  Lathe  and  Its  Uses,"  etc.  Illustrated. 
I2mo #1-75 

MAIN  and  BROWN.— Questions  on  Subjects  Connected  with 

the  Marine  Steam-Engine : 

And  Examination  Papers;  with  Hints  for  their  Solution.  By 
THOMAS  J.  MAIN,  Professor  of  Mathematics,  Royal  "tfaval  College, 
and  THOMAS  BROWN,  Chief  Engineer,  R.  N.  I2mo.,  cloth  .  #1.00 

MAIN  and  BROWN.— The  Indicator  and  Dynamometer : 
With  their  Practical  Applications  to  the  Steam-Engine.     By  THOMAS 
J.  MAIN,   M.  A.  F.  R.,  Ass't    S.    Professor   Royal   Naval   College, 
Portsmouth,  and  THOMAS  BROWN,  Assoc.  Inst.  C.  E.,  Chief  Engineer 
R.  N.,  attached  to  the  R.  N.  Cojlege.     Illustrated.     8vo.  .         $1.00 

MAIN  and  BROWN.— The  Marine  Steam-Engine. 

By  THOMAS  J.  MAIN,  F.  R.  Ass't  S.  Mathematical  Professor  at  the 
Royal  Naval  College,  Portsmouth,  and  THOMAS  BROWN,  Assoc. 
Inst.  C.  E.,  Chief  Engineer  R.  N.  Attached  to  the  Royal  Naval 
College.  With  numerous  illustrations.  8vo. 

MAKINS.— A  Manual  of  Metallurgy: 

By  GEORGE  HOGARTH  MAKINS.  100  engravings.  Second  edition 
rewritten  and  much  enlarged.  I2mo.,  592  pages  .  .  $3-oo 

MARTIN.— Screw-Cutting  Tables,  for  the  Use  of  Mechanical 

Engineers  : 

Showing  the  Proper  Arrangement  of  Wheels  for  Cutting  the  Threads 
of  Screws  of  any  Required  Pitch ;  with  a  Table  for  Making  the  Uni- 
versal Gas-Pipe  Thread  and  Taps.  By  W.  A.  MARTIN,  Engineer. 
8vo 50 

MICHELL. — Mine  Drainage : 

Being  a  Complete  and  Practical  Treatise  on  Direct-Acting  Under* 
ground  Steam  Pumping  Machinery.  With  a  Description  of  a  large 
number  of  the  best  known  Engines,  their  General  Utility  and  thft 
Special  Sphere  of  their  Action,  the  Mode  of  their  Application,  and 
their  Merits  compared  with  other  Pumping  Machinery.  By  STEPHEN 
MICHELL.  Illustrated  by  137  engravings.  8vo.,  277  pages  .  $6.00 

MOLES  WORTH.— Pocket-Book    of    Useful     Formulae     and 

Memoranda  for  Civil  and  Mechanical  Engineers. 
By  GUILFORD  L.  MOLESWORTH,  Member  of  the  Institution  of  Civil 
Engineers,  Chief  Resident  Engineer  of  the  Ceylon  Railway.     Full- 
bound  in  Pocket-book  form      .         .         •         •         -         - 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.          19 

MOORE.— The  Universal  Assistant  and  the  Complete  Me- 
chanic : 

Containing  over  one  million  Industrial  Facts,  Calculations,  Receipts, 
Processes,  Trades  Secrets,  Rules,  Business  Forms,  Legal  Items,  Etc., 
in  every  occupation,  from  the  Household  to  the  Manufactory.  By 
R.  MOORE.  Illustrated  by  500  Engravings.  I2mo.  .  $2.50 

MORRIS. — Easy  Rules  for  the  Measurement  of  Earthworks: 
By  means  of  the  Prismoidal  Formula.  Illustrated  with  Numerous 
Wood-Cuts,  Problems,  and  Examples,  and  concluded  by  an  Exten- 
sive Table  for  finding  the  Solidity  in  cubic  yards  from  Mean  Areas.. 
The  whole  being  adapted  for  convenient  use  by  Engineers,  Surveyorsr 
Contractors,  and  others  needing  Correct  Measurements  of  Earthwork. 
By  ELWOOD  MORRIS,  C.  E.  8vo $1.50 

MAUCHLINE.— The  Mine  Foreman's  Hand-Book 

Of  Practical  and  Theoretical  Information  on  the  Opening,  Venti- 
lating, and  Working  of  Collieries.  Questions  and  Answers  on  Prac- 
tical and  Theoretical  Coal  Mining.  Designed  to  Assist  Students  and 
Others  in  Passing  Examinations  for  Mine  Foremanships.  By 
ROBERT  MAUCHLINE,  Ex-Inspector  of  Mines.  A  New,  Revised  and 
Enlarged  Edition.  Illustrated  by  114  engrarings.  8vo.  337 
pages -k  .  .  .  .  #3.75 

NAPIER.— A  System  of  Chemistry  Applied  to  Dyeing. 
By  JAMES  NAPIER,  F.  C.  S.  A  New  and  Thoroughly  Revised  Edi- 
tion. Completely  brought  up  to  the  present  state  of  the  Science, 
including  the  Chemistry  of  Coal  Tar  Colors,  by  A.  A.  FESQUET, 
Chemist  and  Engineer.  With  an  Appendix  on  Dyeing  and  Calico 
Printing,  as  shown  at  the  Universal  Exposition,  Paris,  1867.  Illus- 
trated. 8vo.  422  pages $3-5o 

NEVILLE.— Hydraulic  Tables,  Coefficients,  and  Formulae,  for 
finding  the  Discharge  of  Water  from  Orifices,  Notches, 
Weirs,  Pipes,  and  Rivers  : 

Third  Edition,  with  Additions,  consisting  of  New  Formulae  for  the 
Discharge  from  Tidal  and  Flood  Sluices  and  Siphons ;  general  infor- 
mation on  Rainfall,  Catchment-Basins,  Drainage,  Sewerage,  Water 
Supply  for  Towns  and  Mill  Power.  By  JOHN  NEVILLE,  C.  E.  M.  R. 
I.  A. ;  Fellow  of  the  Royal  Geological  Society  of  Ireland.  Thicfc 
12ino $5.50' 

NEWBERY.— Gleanings     from     Ornamental     Art    of     every 

style : 

Drawn  from  Examples  in  the  British,  South  Kensington,  Indian, 
Crystal  Palace,  and  other  Museums,  the  Exhibitions  of  1851  and 
1862,  and  the  best  P^nglish  and  Foreign  works.  In  a  series  of  loo 
exquisitely  drawn  Plates,  containing  many  hundred  examples.  B* 
ROBERT  NEWBERY.  4to. $12.50 

NICHOLLS.—  The  Theoretical  and  Practical  Boiler -Maker  and 

Engineer's  Reference  Book: 

Containing  a  variety  of  Useful  Information  for  Employers  of  Laboc 
Foremen  and  Working  Boiler-Makers.  Iron,  Copper,  and  Tinsmiths. 


20        HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 

Draughtsmen,  Engineers,  the  General  Steam-using  Public,  and  for  tha 
Use  of  Science  Schools  and  Classes.  By  SAMUEL  NICHOLLS.  Illus* 
trated  by  sixteen  plates,  I2mo. $2.50 

NICHOLSON.— A  Manual  of  the  Art  of  Bookbinding : 

Containing  full  instructions  in  the  different  Branches  of  Forwarding, 
Gilding,  and  Finishing.  Also,  the  Art  of  Marbling  Book-edges  and 
Paper.  By  JAMES  B.  NICHOLSON.  Illustrated.  I2mo.,  cloth  $2.2$, 

NICOLLS.— The  Railway  Builder: 

A  Hand-Book  for  Estimating  the  Probable  Cost  of  American  Rail* 
way  Construction  and  Equipment.  By  WILLIAM  J.  NICOLLS,  Civil 
Engineer.  Illustrated,  full  bound,  pocket-book  form  .  $2.00 

^ORMANDY.— The  Commercial  Handbook  of  Chemical  An- 
alysis : 

Or  Practical  Instructions  for  the  Determination  of  the  Intrinsic  ot 
Commercial  Value  of  Substances  used  in  Manufactures,  in  Trades, 
and  in  the  Arts.  By  A.  NORMANDY.  New  Edition,  Enlarged,  and 
to  a  great  extent  rewritten.  By  HENRY  M.  NOAD,  Ph.D.,  F.R.S., 
thick  I2mo #5.00 

NORRIS. — A  Handbook  fcr  Locomotive   Engineers  and  Ma- 

chinists : 

Comprising  the  Proportions  and  Calculations  for  Constructing  Loco- 
motives;  Manner  of  Setting  Valves;  Tables  of  Squares,  Cubes,  Areas, 
etc.,  etc.  By  SEFHMUS  NORRIS,  M.  E.  New  edition.  Illustrated, 
I2mo $1.50 

NYSTROM. — A  New  Treatise  on  Elements  of  Mechanics : 
Establishing  Strict  Precision  in  the   Meaning  of  Dynamical  Terms : 
accompanied  with  an  Appendix  on  Duodenal  Arithmetic  and  Me- 
trology.    By  JOHN  W.  NYSTROM,  C.  E.     Illustrated.     8vo.       $2.00 

NYSTROM. — On  Technological  Education  and  the  Construc- 
tion of  Ships  and  Screw  Propellers : 

For  Naval  and  Marine  Engineers.  By  JOHN  W.  NYSTROM,  late 
Acting  Chief  Engineer,  U.  S.  N.  Second  edition,  revised,  with  addi- 
tional matter.  Illustrated  by  seven  engravings.  I2mo.  .  $1.50 

O'NEILL. — A  Dictionary  of  Dyeing  and  Calico  Printing : 

Containing  a  brief  account  of  ail  the  Substances  and  Processes  in 
use  in  the  Art  of  Dyeing  and  Printing  Textile  Fabrics  ;  with  Practical 
Receipts  and  Scientific  Information.  By  CHARLES  O'NEILL,  Analy- 
tical Chemist.  To  which  is  added  an  Essay  on  Coal  Tar  Colors  and 
their  application  to  Dyeing  and  Calico  Printing.  By  A.  A.  FESQUET, 
Chemist  and  Engineer.  With  an  appendix  on  Dyeing  and  Calico 
Printing,  as  shown  at  the  Universal  Exposition,  Paris,  1867.  8vo., 
491  pages |3.50 

ORTON. — Underground  Treasures'. 

How  and  Where  to  P'ind  Them.  A  Key  for  the  Ready  Determination 
of  all  the  Useful  Minerals  within  the  United  States.  By  JAMES 
ORTON,  A.M.,  Late  Professor  of  Natural  History  in  Vassar  College, 
N.  Y.;  Cor.  Mem.  of  the  Academy  of  Natural  Sciences,  Philadelphia, 
and  of  the  Lyceum  of  Natural  History,  New  York ;  author  of  the 
"Andes  and  the  Amazon,"  etc.  A  New  Edition,  with  Additions. 
Illustrated  -  „  $1.9 


HENRY  CAREY  BArRD   &   CO.'S   CATALOGUE.       2j 


OSBORN. — The  Prospector's  Field  Book  and  Guide : 

In  the  Search  for  and  the  Easy  Determination  of  Ores  and  Other 
Useful  Minerals.  By  Prof.  H.  S.  OSBORN,  LL.  D.,  Author  of 
"The  Metallurgy  of  Iron  and  Steel;"  "A  Practical  Manual  of 
Minerals,  Mines,  and  Mining."  Illustrated  by  44  Engravings. 
I2mo $1.50 

OSBORN. — A  Practical  Manual  of  Minerals,  Mines  and  Min- 
ing: 

Comprising  the  Physical  Properties,  Geologic  Positions,  Local  Occur- 
rence  and  Associations  of  the  Useful  Minerals ;  their  Methods  of 
Chemical  Analysis  and  Assay :  together  with  Various  Systems  of 
Excavating  and  Timbering,  Brick  and  Masonry  Work,  during  Driv- 
ing, Lining,  Bracing  and  other  Operations,  etc.  By  Prof.  H.  S. 
OSBORN,  LL.  D:,  Author  of  the  "  Metallurgy  of  Iron  and  Steel." 
Illustrated  by  171  engravings  from  original  drawings.  8vo.  $4-SQ 

OVERMAN.— Thti  Manufacture  of  Steel : 

Containing  the  Practice  and  Principles  of  Working  and  Making  Steel. 
A  Handbook  for  Blacksmiths  and  Workers  in  Steel  and  Iron,  Wagon 
Makers,  Die  Sinkers,  Cutlers,  and  Manufacturers  of  Files  and  Hard- 
ware, of  Steel  and  Iron,  and  for  Men  of  Science  and  Art.  By 
FREDERICK  OVERMAN,  Mining  Engineer,  Author  of  the  "  Manu- 
facture of  Iron,"  etc.  A  new,  enlarged,  and  revised  Edition.  By 
A.  A.  FESQU^T,  Chemist  and  Engineer.  I2mo.  .  .  $1.50 

OVERMAN.— The  Moulder's  and  Founder's  Pocket  Guide  : 
A  Treatise  on  Moulding  and  Founding  in  Green-sand,  Dry-sand,  Loam, 
and  Cement;  the  Moulding  of  Machine  Frames,  Mill-gear,  Hollow 
ware,  Ornaments,  Trinkets,  Bells,  and  Statues ;  Description  of  Moulds 
for  Iron,  Bronze,  Brass,  and  other  Metals ;  Plaster  of  Paris,  Sulphur, 
Wax,  etc. ;  the  Construction  of  Melting  Furnaces,  the  Melting  and 
Founding  of  Metals ;  the  Composition  of  Alloys  and  their  Nature, 
etc.,  etc.  By  FREDERICK  OVERMAN,  M.  E.  A  new  Edition,  to 
which  is  added  a  Supplement  on  Statuary  and  Ornamental  Moulding, 
Ordnance,  Malleable  Iron  Castings,  etc.  By  A.  A.  FESQUET,  Chem- 
ist and  Engineer.  Illustrated  by  44  engravings.  I2mo.  .  $2.OO 

PAINTER,  GILDER,  AND  VARNISHER'S  COMPANION, 
Containing  Rules  and  Regulations  in  everything  relating  to  the  Artf 
of  Painting,  Gilding,  Varnishing,  Glass-Staining,  Graining,  Marbling, 
Sign-Writing,  Gilding  on  Glass,  and  Coach  Painting  and  Varnishing; 
Tests  for  the  Detection  of  Adulterations  in  Oils,  Colors,  etc. ;  and  a 
Statement  of  the  Diseases  to  which  Painters  are  peculiarly  liable,  with 
the  Simplest  and  Best  Remedies.  Sixteenth  Edition.  Revised,  with 
an  Appendix.  Containing  Colors  and  Coloring — Theoretical  and 
Practical.  Comprising  descriptions  of  a  great  variety  of  Additional 
Pigments,  their  Qualities  and  Uses,  to  which  are  added,  Dryers,  and 
Modes  and  Operations  of  Painting,  etc.  Together  with  Chevreul'? 
Principles  of  Harmony  and  Contrast  of  Colors.  I2mo.  Cloth  $1.50 

|>ALLETT.— The  Miller's,  Millwright's,  and  Engineer's  Guide. 
By  HENRY  PALLETT.  Illustrated.  i2mo.  .  .  »  #2.oi 


22          HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 

PERCY. — The  Manufacture  of  Russian  Sheet-Iron. 

By  JOHN  PERCY,  M.  D.,  F.  R.  S.,  Lecturer  on  Metallurgy  at  the 
Royal  School  of  Mines,  and  to  The  Advance  Class  of  Artillery 
Officers  at  the  Royal  Artillery  Institution,  Woolwich ;  Author  of 
"  Metallurgy."  With  Illustrations.  8vo.,  paper  .  .  50  cts. 

PERKINS.— Gas  and  Ventilation  : 

Practical  Treatise  on  Gas  and  Ventilation.  With  Special  Relation 
to  Illuminating,  Heating,  and  Cooking  by  Gas.  Including  Scientific 
Helps  to  Engineer-students  and  others.  With  Illustrated  Diagrams, 
By  E.  E.  PERKINS.  i2mo.,  cloth $1.25 

PERKINS  AND  STOWE.— A  New  Guide  to  the  Sheet-iron 

and  Boiler  Plate  Roller : 

Containing  a  Series  of  Tables  showing  the  Weight  of  Slabs  and  Pilea 
to  Produce  Boiler  Plates,  and  of  the  Weight  of  Piles  and  the  Sizes  of 
Bars  to  produce  Sheet-iron ;  the  Thickness  of  the  Bar  Gauge 
in  decimals ;  the  Weight  per  foot,  and  the  Thickness  on  the  Bar  or 
Wire  Gauge  of  the  fractional  parts  of  an  inch;  the  Weight  per 
sheet,  and  the  Thickness  on  the  Wire  Gauge  of  Sheet-iron  of  various 
dimensions  to  weigh  112  Ibs.  per  bundle;  and  the  conversion  of 
Short  Weight  into  Long  Weight,  and  Long  Weight  into  Short. 
Estimated  and  collected  by  G.  H.  PERKINS  and  J.  G.  STOWE.  $2.50 

POWELL— CHANCE— HARRIS,— The    Principles  of  Glass 

Making. 

By  HARRY  J.  POWELL,  B.  A.  Together  with  Treatises  on  Crown  and 
Sheet  Glass;  by  HENRY  CHANCE,  M.  A.  And  Plate  Glass,  by  H. 
G.  HARRIS,  Asso.  M.  Inst.  C.  E.  Illustrated  i8mo.  .  $i-5c 

PROCTOR. — A  Pocket-Book  of  Useful  Tables  and  Formulae 

for  Marine  Engineers  : 

By  FRANK  PROCTOR.  Second  Edition,  Revised  and  Enlarged. 
Full -bound  pocket-book  form  ......  $1.50 

REGNAULT. — Elements  of  Chemistry: 

By  M.  V.  REGNAULT.  Translated  from  the  French  by  T.  FORREST 
BETTON,  M.  D.,  and  edited,  with  Notes,  by  JAMES  C.  BOOTH,  Melter 
and  Refiner  U.  S.  Mint,  and  WILLIAM  L.  FABER,  Metallurgist  and 
Mining  Engineer.  Illustrated  by  nearly  700  wood-engravings.  Com- 
prising nearly  1,500  pages.  In  two  volumes,  8vo.,  cloth  .  $7.50 

RICHARDS.— Aluminium : 

Its  History,  Occurrence,  Properties,  Metallurgy  and  Applications, 
including  its  Alloys.  By  JOSEPH  W.  RICHARDS,  A.  C.,  Chemist  and 
Practical  Metallurgist,  Member  of  the  Deutsche  Chemische  Gesell- 
schaft.  Illustrated $S-°° 

RIFFAULT,  VERGNAUD,  and  TOUSSAINT.— A  Practical 

Treatise  on  the  Manufacture  of  Colors  for  Painting : 
Comprising  the  Origin,  Definition,  and  Classification  of  Colors;  the 
Treatment  of  the  Raw  Materials ;  the  best  Formulae  and  the  Newest 
Processes  for  the  Preparation  of  every  description  of  Pigment,  and 
the  Necessary  Apparatus  and  Directions  for  its  Use ;  Dryers ;  th« 
Testing.  Application,  and  Qualities  of  Paints,  etc.,  etc.  By  MM. 
RIFFAULT,  VERGNAUD,  and  TOUSSAINT.  Revised  and  Edited  by  M. 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.          23 

F.  MALEPEYRE.  Translated  from  the  French,  by  A.  A.  FESQUET, 
Chemist  and  Engineer.  Illustrated  by  Eighty  engravings.  In  one 
vol.,  8vo.,  659  pages $5.00 

ROPER. — A  Catechism  of  High- Pressure,  or  Non-Condensing 

Steam-Engines  : 

Including  the  Modelling,  Constructing,  and  Management  of  Steam- 
Engines  and  Steam  Boilers.  With  valuable  illustrations.  By  STE- 
PHEN ROPER,  Engineer.  Sixteenth  edition,  revised  and  enlarged. 
l8mo.,  tucks,  gilt  edge $2.00 

ROPER. — Engineer's  Handy-Book: 

Containing  a  full  Explanation  of  the  Steam-Engine  Indicator,  and  its 
Use  and  Advantages  to  Engineers  and  Steam  Users.  With  Formulae 
for  Estimating  the  Power  of  all  Classes  of  Steam-Engines;  also. 
Facts,  Figures,  Questions,  and  Tables  for  Engineers  who  wish  to 
qualify  themselves  for  the  United  States  Navy,  the  Revenue  Service, 
the  Mercantile  Marine,  or  to  take  charge  of  the  Better  Class  of  Sta- 
tionary Steam-Engines.  Sixth  edition.  i6mo.,  690  pages,  tucks, 
gilt  edge #3.50 

ROPER. — Hand-Book  of  Land  and  Marine  Engines  : 
Including  the  Modelling,  Construction*   Running,  and  Management 
of  Lane5  and  Marine  Engines  and  Boilers.     With  illustrations.     By 
STEPHEN  ROPER,  Engineer.    Sixth  edition.     I2mo.,tvcks,  gilt  edge. 

#3-5<> 
ROPER.— Hand-Book  of  the  Locomotive  : 

Including  the  Construction  of  Engines  and  Boilers,  and  the  Construc- 
tion, Management,  and  Running  of  Locomotives.  By  STEPHEN 
ROPER.  Eleventh  edition.  i8mo.,  tucks,  gilt  edge  .  $2.50 

ROPER. — Hand-Book  of  Modern  Steam  Fire- Engines. 
With  illustrations.     By  STEPHEN  ROPER,  Engineer.     Fourth  edition, 
I2mo.,  tucks,  gilt  edge $3-50 

ROPER. — Questions  and  Answers  for  Engineers. 

This  little  book  contains  all  the  Questions  that  Engineers  will  be 
asked  when  undergoing  an  Examination  for  the  purpose  of  procuring 
Licenses,  and  they  are  so  plain  that  any  Engineer  or  Fireman  of  or- 
dinary intelligence  may  commit  them  to  memory  in  a  short  time.  By 
STEPHEN  ROPER,  Engineer.  Third  edition  .  .  .  $3.00 

ROPER. — Use  and  Abuse  of  the  Steam  Boiler. 
By  STEPHEN  ROPER,  Engineer.     Eighth  edition,  with  illustrations. 
i8mo.,  tucks,  gilt  edge       . $2.00 

ROSE. — The  Complete  Practical  Machinist : 

Embracing  Lathe  Work,  Vise  Work,  Drills  and  Drilling,  Taps  and 
Dies,  Hardening  and  Tempering,  the  Making  and  Use  of  Tools, 
Tool  Grinding,  Marking  out  Work,  etc.  By  JOSHUA  ROSE.  Illus- 
trated by  356  engravings.  Thirteenth  edition,  thoroughly  revised 
and  in  great  part  rewritten.  In  one  vol.,  I2mo.,  439  pages  $2.50 

ROSE. — Mechanical  Drawing  Self-Taught : 
Comprising  Instructions  in  the  Selection  and  Preparation  of  Drawing 
Instruments,  Elementary  Instruction  in  Practical  Mechanical  Draw 


24         HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 

ing,  together  with  Examples  in  Simple  Geometry  and  Elementary 
Mechanism,  including  Screw  Threads,  Gear  Wheels,  Mechanical 
Motions,  Engines  and  Boilers.  By  JOSHUA  ROSE,  M.  E.  Illustrated 
by  330  engravings.  8vo.,  313  pages  ....  $4.00 

ROSE.— The  Slide- Valve  Practically  Explained: 

Embracing  simple  and  complete  Practical  Demonstrations  of  tlu 
operation  of  each  element  in  a  Slide-valve  Movement,  and  illustrat- 
ing the  effects  of  Variations  in  their  Proportions  by  examples  care- 
fully selected  from  the  most  recent  and  successful  practice.  By 
JOSHUA  ROSE,  M.E.  Illustrated  by  35  engravings  .  $1.00 

ROSS. — The  Blowpipe  in  Chemistry,  Mineralogy  and  Geology: 
Containing  all  Known  Methods  of  Anhydrous  Analysis,  many  Work- 
ing Examples,  and  Instructions  for  Making  Apparatus.  By  LIEUT.- 
COLONEL  W.  A.  Ross,  R.  A.,  F.  G.  S.  With  120  Illustrations. 
I2mo #2.00 

SHAW.— Civil  Architecture : 

Being  a  Complete  Theoretical  and  Practical  System  of  Building,  con- 
taining  the  Fundamental  Principles  of  the  Art.  By  EDWARD  SHAW, 
Architect.  To  which  is  added  a  Treatise  on  Gothic  Architecture,  etc. 
By  THOMAS  W.  SILLOWAY  and  GEORGE  M.  HARDING,  Architects. 
The  whole  illustrated  by  102  quarto  plates  finely  engraved  on  copper. 
Eleventh  edition.  4to. $7'S° 

SHUNK. — A  Practical  Treatise  on  Railway  Curves  and  Loca- 
tion, for  Young  Engineers. 
By  W.  F.  SHUNK,  C.  E.     I2mo.    Full  bound  pocket-book  form  $2.00 

SLATER. — The  Manual  of  Colors  and  Dye  Wares. 
By  J.  W.  SLATER.     I2mo £3.00 

SLOAN. — American  Houses  : 

A  variety  of  Original  Designs  for  Rural  Buildings.  Illustrated  by 
26  colored  engravings,  with  descriptive  references.  By  SAMUEL 
SLOAN,  Architect.  8vo. $1.50 

SLOAN. — Homestead  Architecture: 

Containing  Forty  Designs  for  Villas,  Cottages,  and  Farm-houses,  with 
Essays  on  Style,  Construction,  Landscape  Gardening,  Furniture,  etc.,, 
etc.  TUustrated  by  upwards  of  200  engravings.  By  SAMUEL  SLOAN, 
Architect.  8vo $3-5° 

SLOANE. — Ho»re  Experiments  in  Science. 

By  T.  O'CoNOR  SLCANE,  E.  M.,  A.  M.,  FI:.  D.  Illustrated  by  91 
engravings.  I2mo.  .......  $i-5a 

SMEATON. — Builder's  Pocket-Companion  : 

Containing  the  Elements  of  Building,  Surveying,  and  Architecture; 
with  Practical  Rules  and  Instructions  corrected  with  the  subject. 

•     By  A.  C.  SMEATON,  Civil  Engineer,  etc.     I2mo.       .         .         $1-5* 

SMITH. — A  Manual  of  Political  Economy. 
By  E.  PESHINE  SMITH.     A  New  Edition,  to  which  is  added  a  full 
Index.     I2mo. $l  25 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.          25 


SMITH.— Parks  and  Pleasure- Grounds: 

Or  Practical  Notes  on  Country  Residences,  Villas,  Public  Parks,  and 
Gardens.  By  CHARLES  H.  J.  SMITH,  Landscape  Gardener  and 
Garden  Architect,  etc.,  etc.  I2mo.  ....  $2.ooi 

SMITH.— The  Dyer's  Instructor: 

Comprising  Practical  Instructions  in  the  Art  of  Dyeing  Silk,  Cotton^ 
Wool,  and  Worsted,  and  Woolen  Goods ;  containing  nearly  800 
Receipts.  To  which  is  added  a  Treatise  on  the  Art  of  Padding;  antjj 
the  Printing  of  Silk  Warps,  Skeins,  and  Handkerchiefs,  and  thei 
various  Mordants  and  Colors  for  the  different  styles  of  such  workj 
By  DAVID  SMITH,  Pattern  Dyer.  I2mo.  .  .  .  $2.00 

SMYTH. — A  Rudimentary  Treatise  on  Coal  and  Coal-Mining. 
By  WARRINGTON  W.  SMYTH,  M.  A.,  F.  R.  G.,  President  R.  G.  S. 
of  Cornwall.  Fifth  edition,  revised  and  corrected.  With  numer- 
ous illustrations.  I2mo.  .  .  .  .  .  .  $I«7S 

SNIVELY.— Tables  for  Systematic  Qualitative  Chemical  AnaU 

ysis. 
By  JOHN  H.  SNIVELY,  Phr.  D.     8vo.         ....        $1.00 

SNIVELY. — The  Elements  of  Systematic  Qualitative  Uiemical 

Analysis : 

A  Hand-book  for  Beginners.    By  JOHN  H.  SNIVELY,  Phr.  D.    l6mo. 

$2.00 

STOKES. — The  Cabinet-Maker  and  Upholsterer's  Companion : 
Comprising  the  Art  of  Drawing,  as  applicable  to  Cabinet  Work; 
Veneering,  Inlaying,  and  Buhl- Work ;  the  Art  of  Dyeing  and  Stain- 
ing Wood,  Ivory,  Bone,  Tortoise-Shell,  etc.  Directions  for  Lacker- 
ing, Japanning,  and  Virnishing;  to  make  French  Polish,  Glues, 
Cements,  and  ComposLi''ns;  with  numerous  Receipts,  useful  to  work 
men  generally.  Bv  STOKES.  Illustrated.  A  New  Edition,  with 
an  Appendix  upor  /ench  Polishing,  Staining,  Imitating,  Varnishing, 
etc.,  etc.  I2mo  ........  $1.25 

STRENGTH  AND  OTHER  PROPERTIES  OF  METALS; 
Reports  of  Experiments  on  the  Strength  and  other  Properties  of 
Metals  for  Cannon.  With  a  Description  of  the  Machines  for  Testing 
Metals,  and  of  the  Classification  of  Cannon  in  service.  By  Officers 
of  the  Ordnance  Department,  U.  S.  Army.  By  authority  of  the  Secre* 
taryofWar.  Illustrated  by  25  large  steel  plates.- Quarto  .  $10.00 

BULLIVAN. — Protection  to  Native  Industry. 
By  Sir  EDWARD  SULLIVAN,  Baronet,  author  of  "  Ten  Chapters  on 
Social  Reforms."     8vo $i.<x> 

SULZ. — A  Treatise  on  Beverages  : 

Or  the  Complete  Practical  Bottler.  Full  instructions  for  Laboratory 
Work,  with  Original  Practical  Recipes  for  all  kinds  of  Carbonated 
Drinks,  Mineral  Waters,  Flavorings,  Extracts,  Syrups,  etc.  By 
CHAS,  HERMAN  SULZ.  Technical  Cherr.ist  and  Practical  Bottler 
Illustrated  by  428  Engravings,  8i#  pp.  ^vo  .  ..  $10.00 


26         HENRY  CAREY  BAIRr?  &  CO.'S  CATALOGUE. 


SYME. — Outlines  of  an  Industrial  Science. 

By  DAVID  SYME.     I2mo.  .  ...         $2.00 

TABLES     SHOWING     THE     WEIGHT     OF     ROUND, 

SQUARE,  AND  FLAT  BAR  IRON,  STEEL,  ETC., 
By  Measurement.     Cloth  ......  63 

TAYLOR.— Statistics  of  Coal : 

Including  Mineral  Bituminous  Substances  employed  in  Arts  and 
Manufactures;  with  their  Geographical,  Geological,  and  Commercial 
Distribution  and  Amount  of  Production  and  Consumption  on  the 
American  Continent.  With  Incidental  Statistics  of  the  Iron  Manu- 
facture. By  R.  C.  TAYLOR.  Second  edition,  revised  by  S.  S.  HALDE- 
MAN.  Illustrated  by  five  Maps  and  many  wood  engravings.  8vo., 
cloth $6.00 

TEMPLETON.— The  Practical  Examinator  on  Steam  and  the 

Steam -Engine : 

With  Instructive  References  relative  thereto,  arranged  for  the  Use  of 
Engineers,  Students,  and  others.  By  WILLIAM  TEMPLETON,  En- 
gineer.  .  I2mo.  ......  •  $1.00 

THAUSING.— The  Theory  and  Practice  of  the  Preparation  of 

Malt  and  the  Fabrication  of  Beer: 

With  especial  reference  to  the  Vienna  Process  of  Brewing.  Elab- 
orated from  personal  experience  by  JULIUS  E.  THAUSING,  Professor 
at  the  School  for  Brewers,  and  at  the  Agricultural  Institute,  Modling, 
near  Vienna.  Translated  from  the  German  by  WILLIAM  T.  BRANNT, 
Thoroughly  and  elaborately  edited,  with  much  American  matter,  and 
according  to  the  latest  and  most  Scientific  Practice,  by  A.  SCHWARZ 
and  DR.  A.  H.  BAUER.  Illustrated  by  140  Engravings.  8vo.,  815 
pages  ....*.  .....  $10.00 

THOMAS. — The  Modern  Practice  of  Photography: 

By  R.  W.  THOMAS,  F.  C.  S.    8vo.  ....  25 

THOMPSON. — Political  Economy.     With  Especial  Reference 

to  the  Industrial  History  of  Nations  : 

By  ROBERT  E.  THOMPSON,  M.  A.,  Professor  of  Social  Science  in  the 
University  of  Pennsylvania.  I2mo.  .  .  .  .  $1.50 

THOMSON.— Freight  Charges  Calculator: 

By  ANDREW  THOMSON,  Freight  Agent.     241110.        .        .        $1.25 

TURNER'S  (THE)  COMPANION: 

Containing  Instructions  in  Concentric,  Elliptic,  and  Eccentric  Turn, 
ing;  also  various  Plates  of  Chucks,  Tools,  and  Instruments;  and 
Directions  for  using  the  Eccentric  Cutter,  Drill,  Vertical  Cutter,  and 
Circular  Rest;  with  Patterns  and  Instructions  for  working  them, 
I2mo $1.2$ 

TURNING  :   Specimens  of  Fancy  Turning   Executed  on  the 

Hand  or  Foot- Lathe : 

With  Geometric,  Oval,  and  Eccentric  Chucks,  and  Elliptical  Cutting 
Frame.  By  an  Amateur.  Illustrated  by  30  exquisite  Photographs. 
4*0. #3.00 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.          27 

VAILE. — Galvanized- Iron  Cornice-Worker's  Manual : 

Containing  Instructions  in  Laying  out  the  Different  Mitres,  and 
Making  Patterns  for  all  kinds  of  Plain  and  Circular  Work.  Also> 
Tables  of  Weights,  Areas  and  Circumferences  of  Circles,  and  other 
Matter  calculated  to  Benefit  the  Trade.  By  CHARLES  A.  VAILE. 
Illustrated  by  twenty-one  plates.  410 $5.00 

VILLE. — On  Artificial  Manures  : 

Their  Chemical  Selection  and  Scientific  Application  to  Agriculture. 
A  series  of  Lectures  given  at  the  Experimental  Farm  at  Vincennes, 
during  1867  and  1874-75.  By  M.  GEORGES  VILLE.  Translated  and 
Edited  by  WILLIAM  CROOKES,  F.  R.  S.  Illustrated  by  thirty-one 
engravings.  8vo.,  450  pages $6.00 

VILLE. — The  School  of  Chemical  Manures  : 

Or,  Elementary  Principles  in  the  Use  of  Fertilizing  Agents.  From 
the  French  of  M.  GEO.  VILLE,  by  A.  A.  FESQUET,  Chemist  and  En- 
gineer. With  Illustrations.  I2mo.  ....  $1.25 

VOQDES. — The  Architect's  and  Builder's  Pocket -Companion 

and  Price-Book : 

Consisting  of  a  Shoit  but  Comprehensive  Epitome  of  Decimals,  Duo- 
decimals, Geometry  and  Mensuration^  with  Tables  of  United  States 
Measures,  Sizes,  Weights,  Strengths,  etc.,  of  Iron,  Wood,  Stone, 
~3rick,  Cement  and  Concretes,  Quantities  of  Materials  in  given  Sizes 
-and  Dimensions  of  Wood,  Brick  and  Stone;  and  full  and  complete 
Bills  of  Prices  for  Carpenter's  Work  and  Painting ;  also,  Rules  for 
•Computing  and  Valuing  Brick  and  Brick  W^ork,  Stone  Work,  Paint- 
ing, Plastering,  with  a  Vocabulary  of  Technical  Terms,  etc.  By 
FRANK  W.  VOGDES,  Architect,  Indianapolis,  Ind.  Enlarged,  revised, 
and  corrected.  In  one  volume,  368  pages,  full-bound,  pocket-book 

form,  gilt  edges #2.00 

Cloth         .  1.50 

VAN  CLEVE.— The  English  and  American  Mechanic : 

Comprising  a  Collection  of  Over  Three  Thousand  Receipts,  Rules, 
and  Tables,  designed  for  the  Use  of  every  Mechanic  and  Manufac- 
turer. By  B.  FRANK  VAN  CLEVE.  Illustrated.  500  pp.  I2mo.  $2.00 

WAHNSCHAFFE.— A  Guide  to  the  Scientific  Examinatioa 

of  Soils: 

Comprising  Select  Methods  of  Mechanical  and  Chemical  Analysis 
and  Physical  Investigation.  Translated  from  the  German  of  Dr.  Fv 
WAHNSCHAFFE.  With  additions  by  WILLIAM  T.  BRANNT.  Illus- 
trated by  25  engravings.  I2mo.  177  pages  .  .  .  $1.50 

WALL. — Practical  Graining : 

With  Descriptions  of  Colors  Employed  and  Tools  Used.  Illustrated 
by  47  Colored  Plates,  Representing  the  Various  Woods  Used  Jc 
Interior  Finishing.  By  WILLIAM  E.  WALL.  8vo.  .  #2.50 

WALTON.— Coal-Mining  Described  and  Illustrated: 

By  THOMAS  H.  WALTON,  Mining  Engineer.  Illustrated  by  24  large 
and  elaborate  Plates,  after  Actual  Workings  and  Apparatus.  #5.00 


2<S         HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 

PVARE.— The  Sugar  Beet. 

Including  a  History  of  the  Beet  Sugar  Industry  in  Europe,  Varieties 
of  the  Sugar  Beet,  Examination,  Soils,  Tillage,  Seeds  and  Sowing^ 
Yield  and  Cost  of  Cultivation,  Harvesting,  Transportation,  Conserva. 
tion,  Feeding  Qualities  of  the  Beet  and  of  the  Pulp,  etc.  By  LEWI« 
S.  WARE,  C.  E.,  M.  E.  Illustrated  by  ninety  engravings.  8vo. 

It* 

WARN.— The  Sheet-Metal  Worker's  Instructor: 

For  Zinc,  Sheet-Iron,  Copper,  and  Tin-Plate  Workers,  etc.  Contain- 
ing  a  selection  of  Geometrical  Problems ;  also,  Practical  and  Simple. 
Rules  for  Describing  the  various  Patterns  required  in  the  different 
branches  of  the  above  Trades.  By  REUBEN  H.  WARN,  Practical 
Tin-Plate  Worker.  To  which  is  added  an  Appendix,  containing 
Instructions  for  Boiler-Making,  Mensuration  of  Surfaces  and  Solidsr 
Rules  for  Calculating  the  Weights  of  different  Figures  of  Iron  and 
Steel,  Tables  of  the  Weights  of  Iron,  Steel,  etc.  Illustrated  by  thirty- 
two  Plates  and  thirty-seven  Wood  Engravings.  8vo.  .  $3.00 

WARNER.— New  Theorems,  Tables,  and  Diagrams,  for  the 
Computation  of  Earth-work : 

Designed  for  the  use  of  Engineers  in  Preliminary  and  Final  Estimates, 
of  Students  in  Engineering,  and  of  Contractors  and  other  non-profes. 
sional  Computers.  In  two  parts,  with  an  Appendix.  Part  I.  A  Prac- 
tical Treatise;  Part  II.  A  Theoretical  Treatise,  and  the  Appendix, 
Containing  Notes  to  the  Rules  and  Examples  of  Part  I.;  Explana^ 
tions  of  the  Construction  of  Scales,  Tables,  and  Diagrams,  and  a 
Treatise  upon  Equivalent  Square  Bases  and  Equivalent  Level  Heights. 
The  whole  illustrated  by  numerous  original  engravings,  comprising, 
explanatory  cuts  for  Definitions  and  Problems,  Stereometric  Scales 
and  Diagrams,  and  a  series  of  Lithographic  Drawings  from  Models  s 
Showing  all  the  Combinations  of  Solid  Forms  which  occur  in  Railroad 
Excavations  and  Embankments.  By  JOHN  WARNER,  A.  M.,  Mining, 
and  Mechanical  Engineer.  Illustrated  by  14  Plates.  A  new,  revised 
and  improved  edition.  8vo.  ......  $4-OO. 

WATSON.— A  Manual  of  the  Hand-Lathe  : 

Comprising  Concise  Directions  for  Working  Metals  of  all  kinds, 
Ivory,  Bone  and  Precious  Woods;  Dyeing,  Coloring,  and  French 
Polishing;  Inlaying  by  Veneers,  and  various  methods  practised  to 
produce  Elaborate  work  with  Dispatch,  and  at  Small  Expense.  Bjr 
EGBERT  P.  WATSON,  Author  of  "  The  Modern  Practice  of  American 
Machinists  and  Engineers."  Illustrated  by  78  engravings.  '$1.50 

WATSON. — The  Modern  Practice  of  American  Machinists  and 

Engineers 

Including  the  Construction,  Application,  and  Use  of  Drills,  Lattoo 
Tools,  Cutters  for  Boring  Cylinders,  and  Hollow-work  generally,  with 
the  most  Economical  Speed  for  the  same ;  the  Results  verified  by 
Actual  Practice  at  the  Lathe,  the  Vise,  and  on  the  Floor.  Togethef 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.          2g 

with  Workshop  Management,  Economy  of  Manufacture,  the  Steam- 
Engine,  Boilers,  Gears,  Belting,  etc.,  etc.  By  EGBERT  P.  WATSON.. 
Illustrated  by  eighty-six  engravings.  I2mo.  .  .  .  jJte-50 

WATSON. — The  Theory  and  Practice  of  the  Art  of  Weaving 

by  Hand  and  Power  • 

With  Calculations  and  Tables  for  the  Use  of  those  connected  with  the 
Trade.  By  JOHN  WATSON,  Manufacturer  and  Practical  Machine- 
Maker.  Illustrated  by  large  Drawings  of  the  best  Power  Looms. 
8vo.  .  $6.00' 

WATT.— The  Art  of  Soap  Making : 

A  Practical  Hand-book  of  the  Manufacture  of  Hard  and  Soft  Soaps, 
Toilet  Soaps,  etc.,  including  many  New  Processes,  and  a  Chapter  on 
the  Recovery  of  Glycerine  from  Waste  Leys.  By  ALEXANDER 
WATT.  111.  I2mo $3.00 

WEATHERLY. — Treatise  on  the  Art  of  Boiling  Sugar,  Crys- 
tallizing, Lozenge-making,  Comfits,  Gum  Goods, 
And  other  processes  for  Confectionery,  etc.,  in  which  are  explained, 
in  an  easy  and  familiar  manner,  the  various  Methods  of  Manufacture 
ing  every  Description  of  Raw  and  Refined  Sugar  Goods,  as  sold  by 
Confectioners  and  others.  I2mo $  1.50 

WIGHT  WICK.— Hints  to  Young  Architects: 

Comprising  Advice  to  those  who,  while  yet  at  school,  are  destined 
to  the  Profession;  to  such  as,  having  passed  their  pupilage,  are  about 
to  travel ;  and  to  those  who,  having  completed  their  education,  are 
about  to  practise.  Together  with  a  Model  Specification  involving  a 
great  variety  of  instructive  and  suggestive  matter.  By  GEORGE 
WIGHTWICK,  Architect.  A  new  edition,  revised  and  considerably 
enlarged;  comprising  Treatises  on  the  Principles  of  Construction 
and  Design.  By  G.  HUSKISSON  GUILLAUME,  Architect.  Numerous 
illustrations.  One  vol.  121110 $2.00 

W  ILL.— Tables  of  Qualitative  Chemical  Analysis. 

With  an  Introductory  Chapter  on  the  Course  of  Analysis.  By  Pro 
fessor  HEINRICH  WILL,  of  Giessen,  Germany.  Third  America^ 
from  the  eleventh  German  edition.  Edited  by  CHARLES  F.  HIMES, 
Ph.  D.,  Professor  of  Natural  Science,  Dickinson  College,  Carlisle,  Pa 
8vo.  .  $1-50 

WILLIAMS.— On  Heat  and  Steam: 

Embracing  New  Views  of  Vaporization,  Condensation,  and  ExpJc 
sion.  By  CHARLES  WYE  WILLIAMS,  A.  I.  C.  E.  Illustrated  8vo. 

#2.50 

WILSON. — A  Treatise  on  Steam  Boilers  : 

Their  Strength,  Construction,  and  Economical  Working.  By  ROBERT 
WILSON.  Illustrated  I2mo.  ......  ,$2.50 

WILSON. — First  Principles  of  Political  Economy: 

With  Reference  to  Statesmanship  and  the  Progress  of  Civilization. 
By  Professor  W.  D.  WILSON,  of  the  Cornell  University.  A  new  and 
revised  edition.  I2mo.  - $i.^c 


30        HENRY   CAREY   BAIRD   &   CO.'S  CATALOGUE. 


WOHLER.— A  Hand-Bookof  Mineral  Analysis: 

By  F.  WOHLER,  Professor  of  Chemistry  in  the  University  of  Gottin- 
gen.  Edited  by  HENRY  B.  NASON,  Professor  of  Chemistry  in  the 
Renssalaer  Polytechnic  Institute,  Troy,  New  York.  Illustrated. 
I2mo $2.50 

WORSSAM.— On  Mechanical  Saws  : 

From  the  Transactions  of  the  Society  of  Engineers.  1869.  By  S.  W. 
WORSSAM,  JR.  Illustrated  by  eighteen  large  plates.  8vo.  $2.50 

RECENT   ADDITIONS. 

BRANNT. — Varnishes,  Lacquers,  Printing  Inks  and  Sealing  - 
Waxes : 

Their  Raw  Materials  and  their  Manufacture,  to  which  is  added  the 
Art  of  Varnishing  and  Lacquering,  including  the  Preparation  of  Put- 
ties and  of  Stains  for  Wood,  Ivory,  Bone,  Horn,  and  Leather.  By 
WILLIAM  T.  BRANNT.  Illustrated  by  39  Engravings,  338  pages. 

I2mo $3.00 

BRANNT — The  Practical  Scourer  and  Garment  Dyer: 

Comprising  Dry  or  Chemical  .^Cleaning ;  the  Art  of  Removing  Stains  ,. 
Fine  Washing ;  Bleaching  and  Dyeing  of  Straw  Hats,  Gloves,  and 
Feathers  of  all  kinds;  Dyeing  of  Worn  Clothes  of  all  fabrics,  in- 
cluding Mixed  Goods,  by  One  Dip;  and  the  Manufacture  of  Soaps 
and  Fluids  for  Cleansing  Purposes.  Edited  by  WILLIAM  T.  BRANNT, 
Editor  of  "  The  Techno-Chemical  Receipt  Book."  Illustrated. 
203  pages.  I2mo.  .......  $2.00 

BRANNT.— Petroleurft . 

Its  History,  Origin,  Occurrence,  Production,  Physical  and  Chemical 
Constitution,  Technology,  Examination  and  Uses;  Together  with 
the  Occurrence  and  Uses  of  Natural  Gas.  Edited  chiefly  from  the 
German  of  Prof.  Hans  Hoefer  and  Dr.  Alexander  Veith,  by  WM. 
T.  BRANNT.  Illustrated  by  3  Plates  and  284  Engravings.  743  pp. 
8vo.  $7-50 

BRANNT.— A  Practical  Treatise  on  the  Manufacture  of  Vine- 
gar and  Acetates,  Cider,  and  Fruit- Wines : 
Preservation  of  Fruits  and  Vegetables  by  Canning  and  Evaporation; 
Preparation  of  Fruit-Butters,  Jellies,  Marmalades,  Catchups,  Pickles, 
Mustards,  etc.  Edited  from  various  sources.  By  WILLIAM  T. 
BRANNT.  Illustrated  by  79  Engravings.  479  pp.  8vo.  $5.00 

BRANNT.— The  Metal  Worker's    Handy-Book   of  Receipts 

and  Processes : 

Being  a  Collection  of  Chemical  Formulas  and  Practical  Manipula- 
tions for  the  working  of  all  Metals  ;  including  the  Decoration  and 
Beautifying  of  Articles  Manufactured  therefrom,  as  well  as  their 
Preservation.  Edited  from  various  sources.  By  WILLIAM  T. 
BRANNT.  Illustrated.  I2mo.  $2.50. 


HENRY  CAREY  BAIRD   &  CO.'S  CATALOGUE.       3I 

DEITE.— A  Practical  Treatise   on   the  Manufacture  cf  Per* 

fumery : 

Comprising  directions  for  making  all  kinds  of  Perfumes,  Sachet 
Powders,  Fumigating  Materials,  Dentifrices,  Cosmetics,  etc.,  with  a 
full  account  of  the  Volatile  Oils,  Balsams,  Resins,  and  other  Natural 
and  Artificial  Perfume-substances,  including  the  Manufacture  of 
Fruit  Ethers,  and  tests  of  their  purity.  By  Dr.  C.  DEITE,  assisted 
by  L.  BORCHERT,  F.  EICHBAUM,  E.  KUGLER,  H.  TOEFFNER,  and 
other  experts.  From  the  German,  by  WM.  T.  BRANNT.  28  Engrav- 
ings. 358  pages.  8vo. $3.00 

2DWARDS. — American    Marine  Engineer,    Theoretical   and 

Practical : 

With  Examples  of  the  latest  and  most  approved  American  Practice. 
By  EMORY  EDWARDS.  85  illustrations.  I2mo.  .  .  $2.50 

EDWARDS.— goo    Examination   Questions  and   Answers: 
For  Engineers  and  Firemen   (Land  and  Marine)  who  desire  to  ob- 
tain a  .United   States  Government  or  State  License.     Pocket-book 
form,  gilt  edge          ........        $1-5° 

POSSELT. — Technology  of  Textile  Design : 

Being  a  Practical  Treatise  on  the  Construction  and  Application  of 
Weaves  for  all  Textile  Fabrics,  with  minute  reference  to  the  latest 
Inventions  for  Weaving.  Containing  also  an  Appendix,  showing 
the  Analysis  and  giving  the  Calculations  necessary  for  the  Manufac. 
hue  of  the  various  Textile  Fabrics.  By  E.  A.  POSSELT,  Head 
Master  Textile  Department,  Pennsylvania  Museum  and  School  of 
Industrial  Art,  Philadelphia,  with  over  1000  illustrations.  292 
pages.  4to $5-°° 

POSSELT.— The  Jacquard  Machine  Analysed  and  Explained : 
With  an  Appendix  on  the  Preparation  of  Jacquard  Cards,  and 
Practical  Hints  to  Learners  of  Jacquard  Designing.  By  E.  A. 
POSSELT.  With  230  illustrations  and  numerous  diagrams.  127  pp. 
4to $3.00 

POSSELT.— The  Structure  of  Fibres,  Yarns  and  Fabrics: 
Being  a  Practical  Treatise  for  the  Use  of  all  Persons  Employed  in 
the  Manufacture  of  Textile  Fabrics,  containing  a  Description  of  the 
Growth  and  Manipulation  of  Cotton,  Wool,  Worsted,  Silk.  Flax, 
Jute,  Ramie,  China  Grass  and  Hemp,  and  Dealing  with  all  Manu- 
facturers' Calculations  for  Every  Class  of  Material,  also  Giving 
Minute  Details  for  the  Structure  of  all  kinds  of  Textile  Fabrics,  and 
an  Appendix  of  Arithmetic,  specially  adapted  for  Textile  Purposes. 
By  E.  A.  POSSELT.  Over  400  Illustrations,  quarto.  .  $10.00 

RICH.— Artistic  Horse-Shoeing: 

A  Practical  and  Scientific  Treatise,  giving  Improved  Methods  of 
Shoeing,  with  Special  Directions  for  Shaping  Shoes  to  Cure  Different 
Diseases  of  the  Foot,  and  for  the  Correction  of  Faulty  Action  in 
Trotters.  By  GEORGE  E.  RICH.  62  Illustrations.  153  pages. 
121110. $1.00 


52       HENRY   CAREY   BAIRD   &  CO.'S  CATALOGUE. 

RICHARDSON.— Practical  Blacksmithing : 

A  Collection  of  Articles  Contributed  at  Different  Times  by  Skilled 
Workmen  to  the  columns  of  "  The  Blacksmith  and  Wheelwright," 
and  Covering  nearly  the  Whole  Range  of  Blacksmithing,  from  the 
Simplest  Job  of  Work  to  some  of  the  Most  Complex  Forgings. 
Compiled  and  Edited  by  M.  T.  RICHARDSON. 

Vol.  I.  210  Illustrations.  224  pages.  I2mo.  .  .  $1.00 
Vol.  II.  230  Illustrations.  262  pages.  I2mo.  .  .  $1.00 
Vol.  III.  390  Illustrations.  307  pages.  I2mo.  .  ,  $1.00 
Vol.  IV.  226  Illustrations.  276  pages.  I2mo.  .  .  $1.00 

RICHARDSON.— The  Practical  Horseshoer: 

Being  a  Collection  of  Articles  on  Horseshoeing  in  all  its  Branches 
which  have  appeared  from  time  to  time  in  the  columns  of  "  1  he 
Blacksmith  and  Wheelwright,"  etc.  Compiled  and  edited  by  M.  T. 
RICHARDSON.  174  illustrations.  .....  $1.00 

ROPER. — Instructions    and    Suggestions    for   Engineers   and 

Firemen : 
By  STEPHEN  ROPER,   Engineer.     i8mo.     Morocco         .         $2.00 

ROPER. — The  Steam  Boiler:  Its  Care  and  Management: 
By  STEPHEN  ROPER,  Engineer.     I2mo.,  tuck,  gilt  edges.         $2.00 

ROPER. — The  Young  Engineer's  Own  Book: 

Containing  an  Explanation  erf  the  Principle  and  Theories  on  which 
the  Steam  Engine  as  a  Prime  Mover  is  Based.  By  STEPHEN  ROPER, 
Engineer.  160  illustrations,  363  pages.  iSino.,  tuck  .  $3-OG 

ROSE.— Modern  Steam -Engines: 

An  Elementary  Treatise  upon  the  Steam-Engine,  written  in  Plain 
language ;  for  Use  in  the  Workshop  as  well  as  in  the  Drawing  Office. 
Giving  Full  Explanations  of  the  Construction  of  Modern  Steanv 
Engines :  Including  Diagrams  showing  their  Actual  operation.  To- 
gether with  Complete  but  Simple  Explanations  of  the  operations  of 
Various  Kinds  of  Valves,  Valve  Motions,  and  Link  Motions,  etc., 
thereby  Enabling  the  Ordinary  Engineer  to  clearly  Understand  the 
Principles  Involved  in  their  Construction  and  Use,  and  to  Plot  out 
their  Movements  upon  the  Drawing  Board.  By  JOSHUA  ROSE.  M.  E. 
Illustrated  by  422  engravings.  Revised.  358  pp.  .  .  $6.00 

ROSE. — Steam  Boilers: 

A  Practical  Treatise  on  Boiler  Construction  and  Examination,  for  the 
Use  of  Practical  Boiler  Makers,  Boiler  Users,  and  Inspectors;  and 
embracing  in  plain  figures  all  the  calculations  necessary  in  Designing 
or  Classifying  Steam  Boilers.  By  JOSHUA  ROSE,  M.  E.  Illustrated 
by  73  engravings.  250  pages.  8vo $2.50 

6CHRIBER.— The  Complete  Carriage  and  Wagon  Painter : 
A  Concise  Compendium  of  the  Art  of  Painting  Carriages,  Wagons.. 
and  Sleighs,  embracing  Full  Directions  in  all  the  Various  Branches, 
including  Lettering,  Scrolling,  Ornair.enting,  Striping,  Varnishing, 
and  Coloring,  with  numerous  Recipes  for  Mixing  Color*.  73  Illus- 
trations. 177  pp.  I2mo #1.00 


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